Psychology Topic 2 Assignment

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ChapChapterter

NeuroscNeuroscience ience as as a a BasisBasis for for Adult Adult DevelopmentDevelopment and and AgingAging

DiscovDiscovering ering DevDevelopmentelopment AdultsAdults’ ’ Views Views About About Brain Brain AgingAging

2.12.1. . Unlocking Unlocking the the BrBrain’ain’s s SecretsSecrets 3737 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Capturing Capturing Images Images of of the the Brain Brain at at WWorkork Doing Doing NNeuroscienceeuroscience

2.2. 2.2. NeurNeuroscience oscience and and the the AAging ging BrainBrain 4141 . . . . . . . . . . . . . . . . . . . . . . . .

HoHow w Is Is the the BBrain rain Organized?Organized? What What Age-Related Age-Related Changes Changes Occur Occur in in NNeurons?eurons? What What Age-Related Age-Related Changes Changes Occur Occur in in NNeurotransmitters?eurotransmitters? How How Do Do We We KnoKnow?w? The The Risk Risk of of FFalling alling and and WhiteWhite Matter Matter HHyperintensitiesyperintensities Linking Linking Structural Structural Changes Changes with with BehaviorsBehaviors

2.3. 2.3. Making Making Sense Sense of of NeurNeuroscience oscience ResearcResearch:h: Explaining Explaining Changes Changes in in BrBrain—Behaviorain—Behavior

RelationsRelations 5454 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Theories Theories and and Models Models of of BBrain–Behavior rain–Behavior ChangesChanges Across Across AAdulthooddulthood Real Real PPeopleeople Oliver Oliver Sacks, Sacks, Brain Brain MMapperapper Plasticity Plasticity and and the the Aging Aging BrainBrain ControControversiesversies The The NeurNeuroethics oethics of of Interventions Interventions toto Address Address BBrain rain AgingAging Social Social PPolicy olicy ImplicationsImplications Neuroscience Neuroscience IInfluencesnfluences on on Social Social PPolicyolicy

In In ReviewReview

IntegrIntegrating ating Concepts Concepts in in DevelopmentDevelopment

KeKey y TTerermsms

Chapter Chapter OutlineOutline 22 LearningLearning ObjectiObjectivesves After After studying studying this this cchapterhapter,, you you will will be be able able to…to…

2.1. 2.1. Describe Describe the the majormajor imaging imaging and and otherother techniques techniques used used inin neuroscience.neuroscience.

2.2. 2.2. Identify Identify and and describedescribe the the major major structures structures ofof the the brain brain and and their their mainmain functions.functions.

2.3. 2.3. Describe Describe the the majormajor theories theories of of age-relatedage-related changes changes in in the the brainbrain and and how how older older adultsadults compensate compensate for for thesethese changes.changes.

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The The most most complex, complex, flexible, flexible, andand adaptive adaptive system system thatthat has has ever ever been been discodiscovered vered sits sits inside inside our our skull—skull—ourour brain, brain, depicted depicted in in FFigure igure 2.1. 2.1. TTripling ripling in in size size duringduring the the first first year year after after birth, birth, our our brain brain reaches reaches 80% 80% of of fullfull size size by by age age 2 2 and and typically typically weighs weighs about about 3 3 pounds pounds bbyy the the time time we we arare e an an adult adult of of about about 25 25 yyears ears of of age. age. TheThe cerebral cerebral cortex cortex (the (the outer outer layer layer involved involved in in higher higher levlevelel thinking) thinking) accounts accounts for for about about 85 85 percent percent of of the the totaltotal weight, weight, keeping keeping in in mind mind that that ovover er 75 75 percent percent of of thatthat weight weight is is waterwater. . (That’(That’s s why why even even being being a a little little dehydehydrdraatetedd is is really really bad bad for for your your brain.)brain.)

Our Our brain brain contains contains about about 100 100 billion billion brain brain cells,cells, called called neurons; neurons; interestiinterestinglyngly, , this this is is about about the the samesame number number of of cells cells as as there there arare e stars stars in in the the Milky Milky WWayay galaxygalaxy. . EEverything verything we we associate associate with with “being “being humanhuman”” happens happens here—our here—our thoughts, thoughts, memories, memories, emotions,emotions, perpersonalitysonality, , quirks, quirks, and and so so on. on. So, So, itit’’s s fitting fitting that that wewe begin begin our our consideration consideration of of the the adult adult developmentdevelopment and and aging aging process process herhere. e. Changes Changes in in the the brain brain araree often often involved involved in in the the changes changes in in behavior behavior and and bodilybodily processes processes we we observe observe over over time.time.

FFigure igure 2.1 2.1 shows shows the the major major structures structures of of the the brainbrain that that are are the the focus focus oof f neuroscience neuroscience rresearch esearch in in adultadult development development and and aging.aging. The The study study of of the the structurestructure

of of the the brain, brain, calledcalledneurneuroanatomoanatomyy, , is is fundamentalfundamental to to neuroscienceneuroscience. . WWe e will will refer refer to to a a number number of of brainbrain regions regions that that exhibit exhibit age-rage-related elated changes changes in in both both structure structure and and function.function.

FFor or much much of of human human historhistoryy, , the the brain brain wasnwasn’’tt considered considered very very important. important. FFor or instance, instance, the the ancientancient Egyptians Egyptians thought thought that that the the heart heart was was the the source source of of humhumanan wisdom wisdom and and the the center center of of emotions emotions and and memorymemory, , so so thatthat was was the the only only organ organ they they kept kept in in a a mummified mummified bodybody. . EEvenven after after people people figured figured out out the the brainbrain’’s s importance, importance, it it kept kept itsits secrets secrets well-guarwell-guarded. ded. Only Only recently recently have have we we had had the the toolstools to to study study the the brain brain in in detail, detail, especially especially in in living living peoplepeople engaged engaged in in various various behaviors behaviors and and activities.activities.

As As we we will will discovdiscoverer, , the the invention invention of of ways ways to to taketake pictures pictures of of the the working working brain brain ““doing doing its its thing” thing” hashas fundamentally fundamentally changed changed our our knowledge knowledge and and understanding understanding of of brain brain processes processes and and functions.functions.This This developmentdevelopment has has coincided coincided with with the the rapid rapid surge surge of of researcresearch h inin neuroscience neuroscience or or the the study study of of the the brain—in brain—in parparticularticular,, typical typical and and atypical atypical cchanges, hanges, along along with with ththe e adaptadapt-- ability ability of of the the aging aging brain.brain. NNeuroscience euroscience enables enables us us toto observe, observe, measure, measure, and and understand understand what what is is going going on on inin a a personperson’’s s brain brain (N(Nunes, unes, 2021). 2021). Images Images such such as as the the oneone in in the the photo photo are are one one way way that that researresearchers chers and and cliniciansclinicians

CorpusCorpus

callosumcallosum

Prefrontal Prefrontal andand

frontal frontal cortexcortex

AmygdalaAmygdala

Limbic Limbic systemsystem

CerebellumCerebellum

HippocampusHippocampus

Cerebral Cerebral cortexcortex

Figure Figure 2.1 2.1 Major Major structures structures of of the the human human brain brain depicting depicting cerebral cerebral cortex, cortex, corpus corpus callosum,callosum, prefrontal prefrontal and and frontal frontal cortex, cortex, cerebellum, cerebellum, hippocampus, hippocampus, limbic limbic system, system, and and amamygdala.ygdala.

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measure measure brain brain activity; activity; we we will will focus focus on on hohow w they they do do thisthis and and what what it it means means as as we we proceed proceed through through the the chapterchapter..

Our Our understanding understanding of of how how the the brain brain worworks ks isis expanding expanding exponentiallyexponentially. . WWe e now now knoknow w through through thethe HHuman uman Connectome Connectome Project, Project, which which uses uses sophisticatedsophisticated studies studies of of brain brain imagery imagery and and computer computer analyses, analyses, whatwhat the the brainbrain’’s s wiring wiring essentially essentially entails—each entails—each hemispherehemisphere of of the the brain brain (that (that is, is, the the left left and and right right halves) halves) containscontains at at least least 180 180 distinct distinct functional functional areas areas that that differ differ in in theirtheir structure, structure, function, function, and and connections connections with with other other brainbrain areas areas (Elam (Elam et et al., al., 2021; 2021; GGlasser lasser et et al., al., 2016). 2016). As As youyou might might imagine, imagine, this this translates translates into into an an extrextremelyemely cocommplicated plicated wiring wiring diagram diagram with with billions billions upon upon billionsbillions of of interconnections.interconnections.

PPerhaps erhaps the the most most important important insightinsight from from neuroscineurosci-- ence ence research research is is the the eevidence vidence that that the the brain brain can can changechange for for the the better better as as we we grogrow w olderolder. . These These findings findings send send anan intriguing intriguing messagemessage to to our our aging aging population. population. HoHoweverwever,, there there is is danger danger in in this. this. As As in in any any rrelatively elatively new new field,field, descriptions descriptions in in the the media, media, especially especially the the internet, internet, maymay extend extend well well beyond beyond the the actual actual scope scope of of our our scientificscientific understanding understanding of of the the brain brain and and misrepresent misrepresent or or exaggerexaggeraatete what what was was actually actually discoverdiscovered, ed, and and provide provide false false hope hope forfor miracle miracle achievements.achievements.

In In this this chapter chapter we we explorexplore e our our understanding understanding ofof the the aging aging brain brain by by examining examining contemporary contemporary theoritheorieses and and recent recent empirical empirical findings findings of of neuroscience neuroscience andand aging. aging. FFirst, irst, we we briefly briefly review review the the various various neuroscience neuroscience theories theories underlying underlying and and the the research research techniques techniques usedused in in studying studying the the brain. brain. NNext, ext, we we focus focus on on cognitivecognitive neuneuroscience roscience and and aging aging including including age-related age-related change change inin brain brain structures, structures, neurochemical neurochemical properties, properties, and and brainbrain function. function. Although Although few few studies studies have have examined examined thethe possible possible effects effects that that culture culture may may have have on on the the aging aging ofof brain brain structures structures and and their their functions functions per per se, se, what what data data existexist reveal reveal no no significant significant differdifferences ences across across culture culture (Chee,(Chee, 2011; 2011; Gutchess Gutchess et et al., al., 20212021). ). WWe e will will then then examine examine thethe

evidence evidence for for neural neural plasticity plasticity in in later later adulthood. adulthood. FFinallyinally,, we we explore explore mormore e developments developments in in the the area area of of socialsocial neuroscience neuroscience and and aging—in aging—in particularparticular, , intriguingintriguing findings findings that that reveal reveal the the neurological neurological underpinnings underpinnings ofof enhanced enhanced emotional emotional processing processing in in older older adulthood adulthood inin contrast contrast to to declines declines in in cogniticognitive ve processing processing such such asas the the ability ability to to control control information information in in the the conscious conscious mind.mind.

Before Before we we explorexplore e some some of of the the scientific scientific research research onon age-related age-related changes changes in in the the brain, brain, complete complete the the DiscoDiscoveringvering Development Development exexercise. ercise. Compare Compare your your findings findings withwith ththe e evidence evidence described described in in the the text text that that follows. follows. WhatWhat sisimmilarities ilarities and and differences differences are are revealed?revealed?

Discovering Discovering DevelopmentDevelopment Adults’ Adults’ Views Views About About Brain Brain AgingAging

In In Chapter Chapter 1, 1, we we briefly briefly considered considered the the existenceexistence and and effect effect of of stereotypes stereotypes about about aging. aging. In In thisthis activityactivity, , wewe’ll ’ll focus focus specifically specifically on on what what adultsadults think think happens happens to to our our brains brains as as we we age. age. In In orderorder to to get get a a sense sense of of this, this, talk talk to to some some people people ofof different different ages ages you you know know and and ask ask them them thethe following following questions:questions:

• • What What happens happens to to the the brain brain as as we we grow grow older?older?

• • What What do do you you think think causcauses es these these changes?changes?

• • How How can can we we tell tell that that there there may may be be somethingsomething cchanging hanging in in a a perperson’son’s s brain?brain?

• • Do Do you you think think there there is is anything anything that that a a personperson can can do do to to cchange hange the the usual usual path path of of cchange?hange?

Compile Compile the the results results from from eaceach h member member of of thethe class. class. As As you you proceed proceed through through the the cchapterhapter,, compare compare them them with with what what neuroscience neuroscience researcresearchh has has uncovered. uncovered. How How do do peoplepeople’’s s beliefs beliefs matcmatch h (or(or not) not) with with the the underlying underlying science?science?

2.1 2.1 Unlocking Unlocking the the Brain’Brain’s s SecretsSecrets

KeKey y QuestionsQuestions • • What What brain brain imaging imaging tectechniques hniques are are used used in in neuroscienceneuroscience

researcresearch?h?

• • What What are are the the main main researcresearch h methods methods used used and and issuesissues studied studied in in neuroscience neuroscience researcresearch h in in adult adult developmentdevelopment and and aging?aging?

At At age age 70, 70, Margaret Margaret wwas as having having trouble trouble movingmoving the the left left side side of of her her bodybody. . With With the the aid aid of of accurateaccurate brain brain imaging imaging tectechniques, hniques, she she was was diagnosed diagnosed asas having having a a tumor tumor located located at at the the front front of of the the rightright motor motor cortex. cortex. (Because (Because the the brain brain is is wired wired inin general general to to control control the the side side of of the the body body oppositeopposite of of the the side side of of the the brain brain in in question, question, movement movement onon one’one’s s lefleft t side side is is controlled controlled by by the the right right side side of of thethe brain brain in in the the area area called called the the motor motor cortex.) cortex.) WithWith image-guided image-guided surgerysurgery, , the the tumor tumor was was removed,removed, and and Margaret Margaret recorecovered vered comforcomfortablytably..

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38 38 Chapter Chapter 2 2 | | Neuroscience Neuroscience as as a a Basis Basis for for Adult Adult Development Development and and AgingAging

HoHow w did did MargaretMargaret’’s s physicians physicians figurfigure e out out what what was was wrongwrong with with her? her? WWe e are are learning learning a a grgreat eat deal deal about about the the rrelationselations between between changes changes in in the the brain brain and and changes changes in in behaviorbehavior thrthrough ough technological technological advances advances in in noninvasivnoninvasive e imagingimaging and and in in assessing assessing psychological psychological functioning functioning (H(Hendersonenderson et et al., al., 2020; 2020; SSugiura, ugiura, 2016).2016). NeuroiNeuroimaging maging is is a a set set ofof tectechniques hniques in in whicwhich h pictures pictures of of the the brain brain are are taktaken en inin various various ways ways to to proprovide vide underunderstanding standing of of both both normalnormal and and abnormal abnormal cognitive cognitive aging.aging. Let’Let’s s explore explore the the differdifferentent types types and and applications applications of of neuroimaging neuroimaging in in more more detail.detail.

CapturCapturing ing ImagImages es of of the the Brain Brain at at WWororkk NNeuroimaging euroimaging allows allows us us to to see see inside inside the the brain brain of of a a livingliving person person to to examine examine the the various various structures structures and and functions functions ofof the the brain brain even even in in a a person person engaged engaged in in a a task. task. NNeuroimeuroim-- aging aging has has revolutionized revolutionized our our understanding understanding of of the the rrelationselations between between our our brain brain and and our our behaviorbehavior, , and and it it is is responsibleresponsible for for an an explosion explosion of of knowledge knowledge oover ver the the past past few few decades.decades. Advances Advances in in neurneuroimaging oimaging have have led led to to much much of of our our underunder-- standing standing of of such such diseases diseases as as dementia dementia (which (which we we will will consider consider in in detail detail in in Chapter Chapter 10) 10) and and to to other other key key insightsinsights into into age-related age-related changes changes that that occur occur to to everyone everyone and and thosethose changes changes that that reflect reflect disease disease or or other other atypical atypical changes.changes.

But But neuroimaging neuroimaging must must be be used used carcarefully efully and and ethiethi-- callycally. . FFor or one one thing, thing, we we are are still still figuring figuring out out which which changeschanges in in the the brain brain are are normative normative and and which which ones ones arare e not. not. WWee need need to to know know what what a a “healthy“healthy” ” brain brain looks looks like like at at differentdifferent points points in in the the human human life life span. span. So So just just because because we we observeobserve a a change change does does not not mean mean anything anything in in and and of of itself itself unlessunless additional additional research research is is done done to to place place it it in in context.context.

TTwo wo neuroimaging neuroimaging techniques techniques are are used used most most often:often:

1.1. StrStructural uctural neurneuroimaging oimaging provides provides highlyhighly detailed detailed images images of of anatomical anatomical features features inin the the brain.brain. The The most most commonly commonly used used structuralstructural neuroimaging neuroimaging methods methods are are X-rays, X-rays, computerizedcomputerized tomography tomography (CT) (CT) scans, scans, and and magnetic magnetic resonanceresonance imaging imaging (MRI). (MRI). Images Images from from structuralstructural neuroimaging neuroimaging techniques techniques are are like like photographsphotographs in in that that they they document document what what a a specific specific brainbrain structure structure looks looks like like at at a a specific specific point point in in time.time. SStructural tructural neuroimaging neuroimaging is is usually usually effective effective atat identifying identifying such such things things as as bone bone fractures, fractures, tumors,tumors, and and other other conditions conditions that that cause cause structuralstructural damage damage in in the the brain, brain, such such as as strokes.strokes.

2.2. Functional Functional neurneuroimaging oimaging provides provides an an indicationindication of of brain brain activity activity but but not not high high anatomanatomical ical detail.detail. The The most most commonly commonly used used functional functional neuroimagingneuroimaging techniques techniques are are single single photon photon emission emission computerizedcomputerized tomography tomography (SPECT), (SPECT), positron positron emissionemission tomography tomography (PET), (PET), functional functional magnetic magnetic resonanceresonance imaging imaging (fMRI), (fMRI), magnetoencephalograpy magnetoencephalograpy (or(or multichannel multichannel encephalography), encephalography), and and near near infraredinfrared spectroscopic spectroscopic imaging imaging (NIRSI). (NIRSI). FFunctionalunctional neuroimaging neuroimaging proprovides vides researchers researchers with with informationinformation about about what what parts parts of of the the brain brain are are active active when when peoplepeople are are doing doing specific specific tasks. tasks. A A typical typical image image will will showshow different different levels levels of of brain brain activity activity as as differdifferent ent colors;colors; for for example, example, red red on on an an image image might might indicate indicate highhigh levels levels of of brain brain activity activity in in that that region, region, wherwhereas eas blueblue might might indicate indicate low low levels levels of of activityactivity..

Images Images sucsuch h as as this this help help us us underunderstand stand how how the the brain brain operates.operates.

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Unlocking Unlocking the the BrBrain’ain’s s SecrSecrets ets 3939

Doing Doing NeurNeuroscienceoscience YYou ou might might wonder wonder if if doing doing studies studies on on the the brain brain wouldwould require require a a special special set set of of designs designs for for rresearch. esearch. CerCertainlytainly,, there there are are special special ways ways to to measurmeasure e brain brain activityactivity, , and,and, as as we we noted noted in in the the previous previous section section special special ways ways ofof taking taking images images of of a a working working brain. brain. But But the the basic basic rresearchesearch designs designs used used in in neuroscience neuroscience are are actually actually the the same same onesones we we encountered encountered in in Chapter Chapter 1 1 with with minor minor modifications.modifications.

ResearcheResearchers rs take take three three main main methodologicalmethodological perspectives perspectives in in studying studying the the neuroscience neuroscience of of aging: aging: thethe neuropsychological, neuropsychological, the the neurneurocorrelational, ocorrelational, andand the the activation activation imaginimaging g approaches approaches (Cabeza, (Cabeza, 2004).2004).TheThe neuropsyneuropsychological chological apapprproach oach compares compares brain brain funcfunc-- tioning tioning of of healthy healthy older older adults adults with with adults adults displaying displaying various various pathologies pathologies and and disorders disorders of of the the brain.brain. InIn this this approach approach researchers researchers arare e interested interested in in whetherwhether persons persons of of any any age age with with damage damage in in specific specific regions regions of of thethe brain brain exhibit exhibit similar similar cognitive cognitive deficits deficits to to those those shown shown bbyy healthy healthy older older adults adults as as documented documented in in other other research. research. IfIf this this is is the the case, case, then then researchers researchers can can conclude conclude that that declinedecline in in cognitive cognitive functifunctioning oning as as we we grogrow w older older may may be be relatedrelated to to underlying underlying changes changes in in the the same same specific specific regions regions of of thethe brain brain observed observed in in the the persons persons with with diagnosed diagnosed and and identiidenti-- fied fied pathologies pathologies or or disorders.disorders.

Let’Let’s s suppose suppose this this type type of of comparison comparison is is mademade between between healthy healthy oldolder er adults adults and and persons persons with with diagdiag-- nosed nosed frontal frontal lobe lobe damage damage (noted (noted in in FFigure igure 2.1).2.1). PPeople eople with with damage damage in in the the frontal frontal lobe lobe display display lolowerwer levels levels of of dopamine dopamine (a (a neurochemical neurochemical substance substance wwe e willwill consider consider a a bit bit later later in in detail), detail), which which results results in in a a decreasedecrease in in how how quickly quickly mental mental processing processing occurs, occurs, termed termed speedspeed of of processing processing (discussed (discussed in in more more detail detail in in Chapter Chapter 6).6). InterInterestinglyestingly, , this this pattern pattern of of sloslowing wing resembles resembles whawhat t isis observed observed in in the the typical typical aging aging trajectortrajectory y of of healthy healthy olderolder adults.adults.

Another Another important important objective objective of of research research using using thisthis approach approach is is to to isolaisolate te the the neural neural or or brain brain mechanismechanismsms that that are are associated associated with with both both normative normative and and atypicalatypical decline decline in in cognitive cognitive functions. functions. These These findings findings stimustimu-- late late the the creation creation of of theories theories by by identifying identifying factors factors thatthat explain explain how how and and why why these these factors factors may may cause cause cognitivecognitive changes changes as as we we age.age.

JJust ust as as we we considered considered in in Chapter Chapter 1 1 in in relationrelation to to adult adult development development and and aging aging research research in in general,general, neuroscience neuroscience researchers researchers use use certain certain rresearch esearch designsdesigns to to study study changes changes in in brain brain structures structures and and processes,processes, which which brings brings us us to to the the two two remaining remaining methodologicalmethodological perspectives.perspectives.

These These techniques, techniques, coupled coupled wiwith th tests tests of of behaviorbehavior such such as as specific specific cognitive cognitive processing processing tasks tasks (e.g., (e.g., recogrecog-- nizing nizing which which pictures pictures you you studied studied frfrom om a a deck deck containing containing pictures pictures you you saw saw and and picturpictures es you you did did not), not), have have shoshownwn quite quite convincingly convincingly that that age-related age-related brain brain changes changes araree responsible responsible for for age-reage-related lated changes changes in in performanceperformance (Betzel, (Betzel, 2022).2022).

In In MMargaretargaret’’s s case, case, an an MRI MRI scan scan was was conducted.conducted. This This identified identified areas areas of of the the brain brain associated associated withwith specific specific functions. functions. The The scan scan prproduced oduced an an imageimage showing showing the the brain brain location location of of interest interest and and the the outline outline ofof a a tumor tumor in in the the area area of of the the brain brain involvinvolved ed in in controllingcontrolling movement.movement.

In In addition addition to to using using MRIMRIs s to to locate locate brain brain tumors,tumors, we we are are interinterested ested in in how how neuroimaging neuroimaging techniquestechniques advance advance our our understanding understanding of of how how the the brain brain changeschanges structurally structurally and and functionally functionally as as we we grow grow olderolder. . Do Do thethe changes changes reflect reflect decline, decline, stabilitystability, , or or perhaps perhaps improimproveve-- ment ment and and compensation? compensation? IIs s there there plasticity plasticity or or grogrowthwth in in the the aging aging brain? brain? These These are are important important questions questions thatthat researchers researchers in in the the field field of of contemporary contemporary neuroscienceneuroscience and and aging aging are are exploring.exploring.

A A neuroscientific neuroscientific approach approach to to the the study study of of agingaging has has several several advantages. advantages. FFor or example, example, the the neuroscienceneuroscience approach approach has has resulted resulted in in the the development development of of newnew, , effeceffec-- tive tive interventions interventions that that are are enhancing enhancing the the quality quality ofof life life of of older older adults adults (Levitin, (Levitin, 22020). 020). IIt t even even has has a a veryvery practical practical side. side. FFor or instance, instance, neuroscience neuroscience research research cancan be be applied applied to to protecting protecting older older adults adults from from financialfinancial exploitation exploitation through through understanding understanding the the connectionconnection between between cognitive cognitive decline decline and and the the ability ability to to understand understand financial financial transactions transactions (Lamar (Lamar et et al., al., 2020; 2020; SSunderaraman underaraman et et al., al., 2021).2021).

These These techniques techniques can can test test models models of of cognitivecognitive aging. aging. NNeuroscience euroscience has has become become increasincreasingly ingly moremore relevant relevant to to cognitivcognitive e aging aging research research as as the the focfocus us hashas expanded expanded beyond beyond studying studying pathologies pathologies of of the the agingaging brain, brain, such such as as Alzheimer’Alzheimer’s s or or PParkinsonarkinson’’s s diseases,diseases, towartoward d investigating investigating normative normative and and healthy healthy agingaging (Aron (Aron et et al., al., 2022). 2022). In In addition, addition, neuroscientific neuroscientific datadata are are more more informativinformative e for for models models of of cognitive cognitive agingaging and and usher usher in in increased increased progrprogress ess in in the the field field by by testingtesting established established theories theories using using cutting-edge cutting-edge methods.methods. FFurthermore, urthermore, examination examination of of the the structure structure and and funcfunc-- tion tion of of the the brain brain has has become become even even more more informative informative forfor cognitive cognitive aging aging research research as as the the focus focus has has shifted shifted frfromom describing describing brain brain activation activation patterns patterns towartoward d explainingexplaining them them and and desigdesigning ning effective effective interventions interventions wherewhere appropriate appropriate (Mar(Marcotte cotte et et al., al., 2022).2022).

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40 40 Chapter Chapter 2 2 | | Neuroscience Neuroscience as as a a Basis Basis for for Adult Adult Development Development and and AgingAging

The The best best solution solution available available to to this this shortcoming shortcoming ofof the the neurocorrelational neurocorrelational approach approach is is to to watch watch the the brainbrain in in action action while while a a person person is is performing performing a a particularparticular behaviorbehavior..The The activation activation imaging imaging apprapproach oach atattemptstempts to to directly directly link link functional functional brain brain activity activity with with cognicogni-- tive tive behavioral behavioral data.data. This This approach approach allows allows rreal-timeeal-time investigation investigation of of changes changes in in brain brain function function as as they they affect affect cognitive cognitive performance performance in in older older adults. adults. As As you you may may havehave surmised, surmised, this this approapproach ach relies relies on on the the funcfunctional tional neuroneuro-- imaging imaging techniques techniques discussed discussed earlier earlier in in this this chapterchapter,, such such as as fMRI. fMRI. FFor or example, example, studies studies using using this this approachapproach have have found found that that younger younger adultsadults’ ’ brains brains show show unilateralunilateral activation activation (i.e., (i.e., activatioactivation n in in only only one one hemisphere hemisphere of of thethe brain) brain) when when they they perform perform specific specific cognitive cognitive tasks, tasks, butbut older older adultsadults’ ’ brains brains tend tend to to have have higher higher activation activation in in bothboth brain brain hemispheres hemispheres when when performing performing the the same same tasks tasks (Aron(Aron et et al., al., 2022). 2022). As As we we will will discuss discuss laterlater, , this this difference difference inin activation activation in in younger younger and and older older adult adult brains brains may may proprovidevide neurological neurological evideevidence nce that that older older adultsadults’ ’ brains brains activelactivelyy compensate compensate for for age-related age-related changes.changes.CompensatoryCompensatory changchanges es are are cchanges hanges that that allow allow older older adults adults toto adapt adapt to to the the inevitable inevitable behavioral behavioral decline decline resultingresulting from from cchanges hanges in in specific specific areas areas of of the the brain.brain. WWe e willwill encounter encounter many many examples examples of of compensatory compensatory changes changes inin oldolder er adultsadults’ ’ behavior behavior throughout throughout the the rest rest of of this this book.book.

Overall, Overall, neuroscience neuroscience has has brought brought an an importantimportant perspective perspective to to studying studying cognitive cognitive aging, aging, influencinginfluencing theories theories of of adulthood adulthood in in several several ways ways (Betzel, (Betzel, 2022;2022; Marcotte Marcotte et et al., al., 2022; 2022; NNeubeck eubeck et et al., al., 2022). 2022). FFirst,irst, theories theories of of brain–behavior brain–behavior relations relations can can be be tested tested usingusing these these approaches. approaches. FFor or instance, instance, age-related age-related changes changes inin how how we we selectivselectively ely direct direct our our attention attention to to specific specific charchar-- acteristics acteristics of of our our environment, environment, as as when when we we drive drive a a carcar,, can can be be validated validated by by examining examining hohow w age-related age-related changeschanges in in performance performance are are associated associated with with both both functional functional andand structural structural changes changes in in the the brain. brain. In In other other words, words, wwe e cancan explain explain how how changes changes in in performance, performance, like like driving, driving, mapmap to to changes changes in in the the brain.brain.

Second, Second, rresearch esearch methods methods that that focus focus on on age-relatedage-related changes changes in in the the structure structure and and functioning functioning of of the the brainbrain can can help help explain explain why why certain certain cognitive cognitive functions, functions, suchsuch as as well-practiced well-practiced tasks, tasks, vocabularyvocabulary, , and and wisdom, wisdom, cancan be be preserved preserved into into old old age age while while other other functions, functions, suchsuch as as processing processing speed, speed, decline decline rapidly rapidly as as people people age. age. BByy carefully carefully tracking tracking which which brain brain structures structures and and functionsfunctions change change in in which which direction—or direction—or in in some some cases cases remainremain the the same—we same—we can can differentiate differentiate and and explain explain seeminglyseemingly contradictory contradictory patterns patterns of of behavior behavior over over time.time.

As As powerful powerful and and useful useful as as they they arare, e, neuroscienneuroscien-- tific tific methods, methods, such such as as fMRI, fMRI, SPECTSPECT, , and and PET PET scans,scans,

The The neurocorneurocorrelational relational apprapproachoach relates relates measures measures of of cognitive cognitive performance performance to to measures measures of of brainbrain structure structure or or functioning.functioning.FFor or example, example, a a researcherresearcher may may be be interested interested in in the the correlation correlation betwbetween een cognitivecognitive behaviorbehavior, , such such as as the the ability ability to to remember remember informationinformation over over short short periods periods of of time, time, and and neural neural structuralstructural measures, measures, such such as as the the volume volume of of the the brain brain or or activity activity in in specific specific areas areas of of the the brain brain (Cabeza (Cabeza & & Dennis, Dennis, 2013;2013; Aron Aron et et al., al., 2022). 2022). Instead Instead of of dirdirect ect measures measures of of brainbrain structure structure or or functioning, functioning, some some researchers researchers invinvestigateestigate the the correlation correlation between between medical medical assessments assessments that that araree associated associated with with the the function function of of specific specific brain brain regionsregions (e.g., (e.g., tests tests of of frontal frontal lobe lobe functioning) functioning) with with the the behavior behavior of of interest interest (such (such as as decision decision making). making). This This approach approach iiss useful useful especially especially when when direct direct measures measures of of brain brain funcfunc-- tioning tioning are are unavailable unavailable or or impractical. impractical. HHoweverowever, , thisthis approach approach is is speculative, speculative, in in that that we we cannot cannot be be certaincertain whether whether the the assessment assessment tests tests of of brain brain functioningfunctioning accurately accurately refreflect lect the the actual actual anatomical anatomical andand functional functional activity activity of of the the specific specific brain brain region region under under investigation.investigation.

A A researcresearch h participant participant being being readied readied for for an an fMRI fMRI neuroimaging neuroimaging studystudy..

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Neuroscience Neuroscience and and the the Aging Aging Brain Brain 4141

MMuch uch adult adult development development and and aging aging research research in in neuroneuro-- science science has has focused focused on on cognitive cognitive aging, aging, examining examining bothboth normative/typical normative/typical and and nonnormative/atypical nonnormative/atypical patternspatterns of of change. change. HistoricallyHistorically, , this this rresearch esearch was was based based mostlymostly on on behavioral behavioral data, data, coupled coupled with with findings findings from from brainbrain autopsies, autopsies, which which together together gave gave rise rise to to the the classic classic theotheo-- ries ries of of cognitive cognitive aging aging (discussed (discussed in in Chapters Chapters 6 6 and and 7). 7). The The rise rise of of neuroscientific neuroscientific methods methods has has stimulatedstimulated research research that that alloallows ws us us to to study study cognitive cognitive processes—processes— and and changes changes in in these these processes—in processes—in the the living living brain brain usingusing the the noninvasive noninvasive brain brain imaging imaging techniques techniques discusseddiscussed earlierearlier. . Knowing Knowing what what is is going going on on inside inside a a livingliving personperson’’s s brain brain gives gives us us enormous enormous insights insights into into bothboth normative normative and and nonnormative nonnormative activityactivity. . IIt t provides provides usus with with a a map map of of which which behaviors behaviors are are based based in in which which localoca-- tion(s) tion(s) of of the the brain brain (N(Nunes, unes, 2021). 2021). For For instance, instance, brainbrain activity activity involved involved in in the the identification identification of of faces faces occurs occurs inin areas areas of of the the brabrain in that that are are among among ththe e first first affected affected byby Alzheimer’Alzheimer’s s disease disease (Y(Yamasaki, amasaki, 2021). 2021). So So changes changes inin brain brain activity activity in in these these rregions egions may may signal signal the the onset onset ofof the the disease disease before before otherother, , more more noticeable noticeable behavioralbehavioral changes changes occuroccur..

This This is is exactly exactly the the type type of of information information in in whichwhich Antonio, Antonio, the the man man in in the the vignette, vignette, would would be be interested.interested. TTo o make make these these types types of of discoveries, discoveries, we we must must first first havhavee a a large large knowledge knowledge base base of of hohow w the the brain brain ages. ages. That That isis what what we we will will consider consider in in this this module.module.

WWe e will will start start with with an an overview overview of of major major brainbrain structures structures essential essential to to know know with with rrespect espect to to age-relatedage-related changes. changes. Then Then we we will will focus focus on on one one area area in in particularparticular,, the the prefrontal prefrontal cortex, cortex, that that is is involved involved in in many many keykey cognitive cognitive processes processes as as a a prime prime example example of of the the complexcomplex patterns patterns of of age-related age-related changes changes that that occuroccur. . WWe’e’llll consider consider the the breadth breadth of of involvement involvement of of the the prprefrontalefrontal cortex cortex and and several several age-related age-related changes changes in in that that involveinvolve-- ment. ment. All All along, along, we we wilwill l be be sure sure to to identify identify hohow w ageage changes changes in in specific specific parts parts of of the the brain brain are are linked linked toto everyday everyday behaviors.behaviors.

How How Is Is the the BrBrain ain OrgOrganized?anized? The The human human brain brain is is an an amazingly amazingly complex complex organ. organ. IIt t stillstill remains remains more more flexible flexible and and capable capable than than any any computercomputer,, handling handling billions billions of of computations computations very very rapidly rapidly andand providing providing us us with with the the wide wide range range of of emotions emotions wwe e expeexpe-- rience. rience. NNeedless eedless to to saysay, , the the strstructure ucture of of such such a a complexcomplex organ organ is, is, well, well, complex.complex.At At the the most most basic basic level, level, thethe brain brain is is made made up up of of cells cells called called neuronsneurons, , an an example example ofof which which is is shown shown in in FFigure igure 2.2.2.2.Key Key structural structural features features ofof the the neuron neuron are are the the dendrdendritesites, , whicwhich h act act liklike e antennasantennas

have have limitations limitations (H(Hurley urley et et al., al., 2020). 2020). Like Like any any set set ofof tools, tools, neuroscience neuroscience techntechniques iques must must be be used used appropriappropri-- ately ately and and ethicallyethically, , and and research research emploemploying ying them them needsneeds to to include include participants participants that that reflect reflect the the diversity diversity of of thethe whole whole population. population. NNeverevertheless, theless, advances advances in in the the field field ofof neuroscience neuroscience have have had had a a major major impact impact on on our our underunder-- standing standing of of cognitive cognitive aging aging because because they they have have forced forced aa rethinking rethinking of of the the typical typical aging aging process process and and under under whatwhat conditions conditions an an atypical atypical trajectory trajectory may may occuroccur..

Adult Adult DevDevelopment elopment in in ActionAction

How How would would a a physician physician decide decide whether whether toto use use structural structural neurneuroimaging oimaging or or functionalfunctional neuroimaging neuroimaging to to aid aid in in a a clinical clinical diagnosis?diagnosis?

Review Review QuestionsQuestions 2.1 2.1 The The Neuroscience Neuroscience ApprApproachoach • • Describe Describe the the major major structural structural and and functionalfunctional

neuroimaging neuroimaging tectechniques. hniques. How How do do they they differ?differ? What What do do they they measure?measure?

• • Describe Describe the the neuroscience neuroscience methodologicalmethodological perspectiperspectives ves used used to to study study the the aging aging brain. brain. WhatWhat are are their their strengths strengths and and their their limitations?limitations?

2.22.2 Neuroscience Neuroscience and and the the AgingAging BrainBrain

KeKey y QuestionsQuestions • • How How is is the the brain brain organizorganized ed structurally?structurally?

• • What What are are the the basic basic cchanges hanges in in neurons neurons as as we we age?age?

• • What What cchanges hanges occur occur in in neurotransmitters neurotransmitters with with age?age?

• • How How do do age-related age-related structural structural brain brain cchanges hanges map map toto behavior?behavior?

Antonio Antonio is is 73, 73, and and he he is is worried worried aboutabout contracting contracting AlzheimerAlzheimer’’s s disease. disease. He He remembersremembers that that his his father father became became disoriented disoriented at at this this age age andand had had trouble trouble remembering remembering things things that that he he had had justjust been been told. told. How How can can Antonio Antonio find find out out if if his his brain brain isis aging aging normatively normatively or or atypically?atypically?

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42 42 Chapter Chapter 2 2 | | Neuroscience Neuroscience as as a a Basis Basis for for Adult Adult Development Development and and AgingAging

• • The The , , at at the the bacback k of of the the brain,brain,cerebellumcerebellum controls controls equilibrium equilibrium and and the the coordination coordination ofof fine fine motor motor movements, movements, and and it it may may be be ininvolvedvolved in in some some cognitive cognitive functions.functions.

• • The The , , located located in in the the middle middle ofofhippocampushippocampus the the brain, brain, is is a a key key structure structure associated associated withwith memorymemory..

• • The The is is a a set set of of brain brain structuresstructureslimbic limbic system system invinvolved olved with with emotion, emotion, motimotivation, vation, andand long-term long-term memorymemory, , among among other other functions.functions. For For adult adult development development and and aging aging researcresearch,h, the the most most important important components components of of the the limbiclimbic system system incinclude lude the the amamygdalaygdala and and thethe hippocampus.hippocampus.

Additional Additional brain brain structures structures and and their their functional functional aspects aspects willwill be be pointed pointed out out when when necessary necessary as as we we move move through through thisthis chapterchapter. . NNext, ext, we we will will briefly briefly consider consider some some of of the the basics basics ofof how how the the brain brain works, works, and and the the age age changes changes that that occuroccur..

What What AgAge-Related e-Related ChangChanges es Occur Occur inin NeurNeurons?ons? Several Several changes changes occur occur with with age age in in neurneurons ons that that interfereinterfere with with their their ability ability to to transmit transmit information information throughoutthroughout the the brain brain (Whalley(Whalley, , 2015). 2015). For For one one thing, thing, as as wwe e ageage the the number number of of neurons neurons in in the the brain brain declines. declines. MMoreore important, important, though, though, are are the the structural structural changes changes thatthat occur occur normatively: normatively: decrdecreases eases in in the the complexitycomplexity, , size,size, and and number number of of dendrites dendrites (so(so less less information information getsgets passed passed along along from from neuron neuron to to neuron); neuron); the the devdevelopmentelopment of of tangles tangles in in the the fibers fibers that that make make up up the the axon axon (greatly(greatly affecting affecting how how easily easily information information is is transmitted transmitted withinwithin each each neuron); neuron); and and increases increases in in the the deposit deposit of of certaincertain proteins proteins in in and and around around neurons neurons (also (also interfering interfering withwith the the transmission transmission of of information information from from neuron neuron to to neuron).neuron).

to to receive receive signals signals from from other other nearby nearby neurons, neurons, andand the the axonaxon, , whicwhich h is is parpart t of of the the neuron neuron containing containing thethe neurofibersneurofibers, , whicwhich h are are the the structures structures that that carry carry inforinfor-- mation mation inside inside the the neuron neuron fromfrom the the dendrites dendrites to to thethe terterminal minal brancbrancheshes, , whicwhich h are are the the endpoints endpoints of of thethe neuron.neuron. NNeurons eurons do do not not physically physically touch touch each each otherother. . InIn order order for for information information to to be be passpassed ed from from one one neuronneuron to to anotheranother, , the the terminal terminal brancbranches hes release release cchemicalshemicals called called neurotrneurotransmitansmittersters that that travel travel across across the the spacespace between between neurons, neurons, called called the the , , where where they they arearesynapsesynapse received received by by the the dendrites dendrites of of the the next next neuron.neuron.

Refer Refer back back to to FFigure igure 2.1 2.1 on on page page 36. 36. The The cerebrcerebral al cortcortex ex is is the the outermost outermost part part of of the the brain. brain. It It consists consists of of two two hemispheres hemispheres (left ( left and and right) right) that that areare connected connected by by a a thicthick k bundle bundle of of neurons neurons called called thethe corcorpus pus callosumcallosum.. MMuch uch of of neuroscience neuroscience researchresearch focuses focuses on on the the cerebral cerebral cortex, cortex, mainly mainly because because it it is is inin the the cerebral cerebral cortex cortex that that the the functions functions most most peoplepeople consider consider as as defining defining what what it it means means to to be be human human reside.reside.

Each Each region region of of the the brain brain has has distinguishing distinguishing featurfeatureses that that relate relate to to tthe he specific specific functions functions those those rregionegionss control. control. FFor or example, example, in in most most right-handed right-handed people,people, language language processing processing is is associated associated primarily primarily with with thethe left left hemisphere, hemisphere, whereas whereas rrecognizing ecognizing nonspeechnonspeech sounds, sounds, emotions, emotions, and and faces faces is is associated associated with with the the rightright hemisphere. hemisphere. FFor or the the study study of of adult adult development development andand aging, aging, the the follofollowing wing are are key key rregions egions to to recognize recognize andand understand:understand: • • The The prefrprefrontal ontal and and frfrontal ontal cortcortex ex is is intimatelyintimately

invinvolved olved in in higherhigher-order -order exexecutive ecutive functionsfunctions sucsuch h as as the the ability ability to to makmake e and and carcarry ry out out plans,plans, switcswitch h between between tasks, tasks, and and maintain maintain attentionattention and and focus, focus, and and it it connects connects with with other other key key brainbrain structures structures that that are are invinvolved olved with with emotion.emotion.

Figure Figure 2.2 2.2 A A typical typical neuron neuron showing showing dendrites, dendrites, axon, axon, and and terminalterminal brancbranches.hes.

DendritesDendrites

Cell Cell bodybody

TerminalTerminal branchesbranches

AxonAxon

Direction Direction of of information information flowflow

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Neuroscience Neuroscience and and the the Aging Aging Brain Brain 4343

health health of of the the white white matter matter (Emsell (Emsell et et al., al., 2016). 2016). BBy y usingusing DTI, DTI, studies studies examining examining WMH WMH have have demonstrated demonstrated thatthat deterioration deterioration of of white white matter matter may may rrepresent epresent a a cause cause ofof increased increased dysfunction dysfunction in in the the prefrprefrontal ontal cortex cortex in in olderolder adults. adults. (DTI (DTI is is also also used used toto differentiate differentiate betbetween ween neuroneuro-- logical logical effects effects of of LLyme yme disease disease [a [a disease disease transmitted transmitted byby deer deer ticks] ticks] and and multiple multiple sclerosis.) sclerosis.) As As we we will will learn learn laterlater,, deterioration deterioration of of the the prefrontal prefrontal cortex cortex has has importantimportant implications implications for for cognitive cognitive functioning functioning in in late late adulthood.adulthood.

Of Of equal equal importance importance is is the the fact fact that that WMH WMH araree linked linked to to cerebrocerebrovascular vascular diseases diseases (e.g., (e.g., stroke stroke resultingresulting from from hypertension) hypertension) ththat at in in turn turn are are associated associated with with thethe progression progression of of dementia. dementia. WMH WMH is is also also associated associated withwith increased increased risk risk for for falling falling (Crockett (Crockett et et al., al., 2022). 2022). HHowow these these connections connections are are discerned discerned is is the the focus focus of of the the HHowow Do Do WWe e Know? Know? feature.feature.

The The good good news news is is that that WMH WMH may may be be prevpreventableentable and and be be treated treated through through medication medication and and changes changes inin lifestyle. lifestyle. FFor or instance, instance, Crockett Crockett and and colleagues colleagues (2022)(2022) found found that that physical physical activity activity may may hold hold promise promise in in mitimiti-- gating gating the the effects effects of of WMH WMH on on falling, falling, as as noted noted in in thethe HoHow w Do Do WWe e Know? Know? feature.feature.

These These studies studies proprovide vide a a key key example example of of howhow DTI DTI is is used used in in diagnosing diagnosing serious serious diseases diseases in in order order toto start start treatment treatment earlier earlier than than would would occur occur otherwise.otherwise. ResearResearchers chers and and clinicians clinicians alike alike urge urge cacaution, ution, though,though, in in not not overinterproverinterpreting eting the the correlational correlational data data betweenbetween the the sheer sheer number number of of WMH WMH and and behaviors, behaviors, as as it it rremainsemains to to be be seen seen whether whether WMH WMH actually actually cause cause disease disease oror behavioral behavioral change, change, or or merely merely reflect reflect a a differdifferent ent underunder-- lying lying cause cause (Y(Yassi assi & & Campbell, Campbell, 2021).2021).

What What AgAge-Related e-Related ChangChanges es Occur Occur inin NeurNeurotrotransmitansmitters?ters? As As noted noted earlierearlier, , because because neurons neurons do do not not touch touch eacheach otherother, , information information transmission transmission from from one one neuron neuron toto another another occurs occurs mainly mainly chemically chemically via via neurotransmitters.neurotransmitters. Advances Advances havhave e been been made made in in measuring measuring changes changes inin neurotransmitters neurotransmitters in in the the aging aging brain. brain. Let’Let’s s explore explore somesome of of the the key key findings.findings.

Dopamine.Dopamine. One One neurotransmitter neurotransmitter that that has has rreceivedeceived a a great great deal deal of of attention attention is is dopamine.dopamine.DopamineDopamine iiss a a neurotransmitneurotransmitter ter associated associated with with higherhigher-level-level cognitive cognitive functioning functioning liklike e inhibiting inhibiting thoughts, thoughts, attenatten-- tion, tion, and and planning, planning, as as well well as as emotion, emotion, movement,movement, and and pleasure pleasure and and pain. pain. CollectivelyCollectively, , the the neurons neurons thatthat use use dopamine dopamine are are called called the the dopaminergic dopaminergic systsystem.em. FFor or example, example, high high dopamine dopamine levels levels are are linked linked to to cognitivecognitive processing processing that that is is effortful effortful and and deliberate, deliberate, but but not not to to thethe

The The number number of of potential potential connections connections also also declines, declines, asas measured measured by by the the number number of of synapses synapses among among neurons.neurons.

InterestinglyInterestingly, , these these same same changes changes occur occur but but inin much much greater greater numbers numbers in in diseases diseases such such as as AlzheimerAlzheimer’’ss disease, disease, leading leading some some researchers researchers to to speculate speculate thatthat there there may may be be a a link link between between normative normative brain brain aging aging andand nonnormative nonnormative brain brain aging aging havinghaving to to do do with with the the speedspeed and and the the number number of of changes, changes, not not in in the the kind kind of of changeschanges that that occuroccur. . In In other other worwords, ds, the the same same changes changes occur occur inin normative normative and and nonnormative nonnormative brain brain aging; aging; there there arare e justjust many many more more of of them them in in atypical atypical brain brain aging.aging.

ImportantlyImportantly, , even even though though much much of of the the age age changechange in in neurons neurons rreflects eflects decreasedecrease and and decrement, decrement, thithis s doesdoes not not mean mean that that change change is is only only negative. negative. On On the the contrarycontrary,, we we will will encounter encounter evidence evidence later later in in the the chapter chapter for for thethe generation generation of of new new and and complex complex neuronal neuronal connections,connections, with with increased increased complexity complexity of of dendrites. dendrites. These These posiposi-- tive tive changes changes occur occur in in rresponse esponse to to new new learning learning and and thethe development development of of more more efficient efficient ways ways of of processing. processing. As As aa result, result, the the full full story story of of age-related age-related changes changes in in neurons neurons isis one one of of both both decline decline and and improvimprovement.ement.

White White MatMatter ter HyperHyperintensities.intensities. One One of of the the mostmost important important structural structural changes changes relating relating to to neurons neurons overover-- all all is is the the declining declining health health of of the the brainbrain’’s s white white mattermatter,, termed termed white white matter matter hyperintensities hyperintensities (WMH).(WMH).WhiteWhite mattmatter er referrefers s to to neurons neurons that that are are covered covered by by myelin,myelin, an an insulating insulating sheath, sheath, that that transmit transmit information information fromfrom one one part part of of the the cerebral cerebral corcortex tex to to another another or or fromfrom the the cerebral cerebral cortex cortex to to other other parparts ts of of the the brain. brain. WhiteWhite mattmatter er hyperhyperintensities intensities are are determined determined by by the the obserobser-- vation vation of of high high signal signal intensity intensity or or a a bright, bright, spottyspotty appearance appearance on on MRI MRI images, images, whicwhich h indicate indicate brainbrain pathologiespathologies (Habes (Habes et et al., al., 2016; 2016; TTubi ubi et et al., al., 2020).2020).

White White matter matter hyperintensities hyperintensities were were once once thoughtthought to to be be simply simply generic generic indicators indicators of of aging. aging. That’That’s s not not thethe view view anymore anymore (T(Tubi ubi et et al., al., 2020). 2020). MMuch uch research research hashas shown shown that that WMH WMH are are clearly clearly associated associated with with progrprogressiveessive cognitive cognitive impairment, impairment, a a two-fold two-fold increase increase in in the the risk risk ofof dementia, dementia, and and a a three-fold three-fold increase increase in in the the risk risk of of strstroke.oke. The The prevalence prevalence of of WMH WMH increases increases with with increasing increasing circucircu-- latory latory system system risk risk factors, factors, such such as as hyperhypertension, tension, diabetes,diabetes, and and smoking. smoking. Risk Risk factor factor exposure exposure appears appears particularlyparticularly detrimental detrimental if if it it occurs occurs in in middle middle age.age.

White White matter matter does does show show some some normative normative deteriodeterio-- ration ration with with increasing increasing age.age. A A neuroimaging neuroimaging methodmethod calledcalled diffusion diffusion ttensor ensor imaging imaging (DTI) (DTI) is is a a type type ofof magnetic magnetic resonance resonance imaging imaging (MR(MRI) I) that that assessesassesses the the rate rate and and direction direction that that water water difdiffuses fuses through through thethe white white matmatterter.. This This results results in in an an index index of of the the structuralstructural

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44 44 Chapter Chapter 2 2 | | Neuroscience Neuroscience as as a a Basis Basis for for Adult Adult Development Development and and AgingAging

How How Do Do WWe e Know?Know? The The Risk Risk of of Falling Falling and and White White Matter Matter HyperintensitiesHyperintensities

What What werwere e the the results?results? Based Based on on mappingmapping of of lesions lesions in in neural neural networks, networks, significantsignificant correlations correlations were were found found between between the the percentagepercentage of of WMH-related WMH-related disruption disruption of of the the dorsal dorsal attentionattention network network and and the the PPPPA A score score and and betweenbetween disruption disruption of of the the sensorimotor sensorimotor and and ventralventral attention attention networks networks with with foam foam swswayay. . There There werewere no no significant significant associations associations with with eyes eyes open open swaysway or or walking walking speed. speed. PhPhysical ysical actiactivity vity moderated moderated thethe association association between between the the dorsal dorsal (top) (top) attentionattention network network and and PPPPA A score. score. This This intriguing intriguing finding finding isis noted noted in in Figure Figure 2.4.2.4.

What What did did the the invinvestigators estigators conclude?conclude? In In olderolder adults adults with with cerebral cerebral small small vessel vessel disease disease thethe disruption disruption to to the the sensorimotorsensorimotor, , dordorsal sal atattention,tention, and and ventral ventral attention attention networks networks as as a a result result ofof WMH WMH may may underlie underlie the the greater greater fall fall risk risk evidentevident in in this this population. population. HoweverHowever, , physical physical activityactivity may may be be an an important important lifestyle lifestyle factor factor by by whicwhichh to to moderate moderate these these relationships, relationships, becausebecause certain certain types types of of phphysical ysical actiactivity vity are are known known toto lower lower the the risk risk of of falling. falling. Future Future researcresearch h shouldshould investiginvestigate ate whether whether physical physical activity activity should should bebe recommended recommended in in the the clinical clinical management management ofof older older adults adults with with cerebral cerebral small small vessel vessel disease.disease.

Who Who werwere e the the invinvestigatestigators, ors, and and whatwhat was was the the aim aim of of the the study?study?Previous Previous researcresearch h hashas indicated indicated that that WMH WMH are are associated associated with with greatergreater risk risk of of falls falls and and slow slow walking walking speed speed in in olderolder adults adults with with cerebral cerebral small small vessel vessel disease.disease. Whether Whether these these problems problems are are caused caused by by thethe disruption disruption of of large-scale large-scale functional functional neuralneural networks networks is is uncertain, uncertain, though. though. RRacachel hel CrocCrockkettett and and a a large large team team of of researcresearcherhers s (2022) (2022) wanted wanted toto find find out.out.

Who Who werwere e the the participants participants in in the the study?study? A A total total of of 164 164 older older adults adults with with cerebral cerebral smallsmall vessel vessel disease disease who who live live in in metropolitanmetropolitan VVancouverancouver, , Canada, Canada, parparticipated. ticipated. All All of of themthem were were screened screened for for dementia, dementia, and and all all livedlived independentlyindependently. . Cerebral Cerebral small small vessel vessel diseasedisease is is the the most most common common type type of of blood blood vesselvessel disease disease in in the the brain, brain, in in whicwhich h blood blood flow flow to to thethe brain brain is is disrupted disrupted in in the the small small blood blood vesselsvessels (arterioles (arterioles and and capillaries). capillaries). The The disease disease cancan occur occur in in any any orgorgan; an; in in the the brain brain it it causescauses memory memory and and other other cognitive cognitive impairment,impairment, as as well well as as falls.falls.

How How did did the the ininvestigatvestigators ors measure measure the the ttopicopic of of interinterest?est?All All participants participants were were givengiven (1) (1) the the Physiological Physiological PProfile rofile Assessment Assessment (PP(PPA),A), a a five-component five-component measure measure of of the the risk risk of of falling;falling; (2) (2) two two additional additional measures measures of of body body swayingswaying (one (one with with eyes eyes open, open, and and one one standing standing on on aa foam foam cushion cushion termed termed “foam “foam sway”);sway”); (3) (3) measures measures of of a a person’person’s s usual usual speed speed ofof walking; walking; (4) (4) a a questionnaire questionnaire about about ooverallverall physical physical activity; activity; and and (5) (5) a a MRI MRI to to measure measure WMHWMH as as well well as as lesions lesions in in specific specific neural neural networks.networks. The The neural neural networks networks in in question question were were the the dorsaldorsal attention attention network network and and the the ventral ventral atattentiontention network; network; their their location location in in the the brain brain is is noted noted inin Figure Figure 2.3. 2.3. These These attention attention networks networks are are ininvolvedvolved in in a a wide wide variety variety of of cognitive cognitive process, process, includingincluding the the noticing noticing of of pain.pain.

What What was was the the design design of of the the ststudy?udy? The The researcresearcherhers s used used a a cross-sectional cross-sectional design, design, and and itit was was a a corcorrelational relational studystudy..

WWere ere therthere e ethical ethical concerns concerns with with the the ststudy?udy? All All participants participants were were proprovided vided informed informed consentconsent documents documents in in writing.writing.

FEFFEFIPS/SPLIPS/SPL

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Figure Figure 2.3 2.3 DorDorsal sal and and ventral ventral attention attention networksnetworks Anatomy Anatomy of of the the vventral entral and and dorsal dorsal atattention tention netnetworks. works. FEF: FEF: FFrontalrontal eyeye e field, field, IPS/SPL: IPS/SPL: Intra Intra parietal parietal sulcus/supesulcus/superior rior parietparietal al lobe, lobe, TPJ:TPJ: TTemporo-parietemporo-parietal al junction, junction, IFG/MFG: IFG/MFG: InfInferior erior frontal frontal gyrus/medialgyrus/medial frontal frontal gyrus.gyrus.

Source: Source: TTorta, orta, DD. . M., M., Legrain, Legrain, VV., ., Mouraux, Mouraux, A., A., & & VValentini, alentini, E. E. (20(20117).7). AtAttention tention to to pain! pain! A A neurocognitive neurocognitive perspective perspective on on atattentionaltentional modulation modulation of of pain pain in in neuroimaging neuroimaging studies. studies. CorteCortex, x, 89,89, 1 120–134.20–134. hthttps://doi.org/1tps://doi.org/10.10.100116/j.cortex.206/j.cortex.201177.0.011.0.0110, 0, Figure Figure 2, 2, p. p. 1123.23.

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Neuroscience Neuroscience and and the the Aging Aging Brain Brain 4545

fewer fewer age age differencdifferences es are are observed observed in in more more automautomaticatic tasks, tasks, like like judging judging the the familiarity familiarity of of information. information. OvOveraerall, ll, the the studies studies using using neuroscience neuroscience methods methods to to examineexamine changchanges es in in the the dopaminergic dopaminergic system system with with increasing increasing age age suggest suggest that that changes changes in in dopamine dopamine levels levels play play a a majormajor role role in in cognitive cognitive aging aging and and may may explain explain why why effortful effortful andand not not automatic automatic processes processes show show mormore e age-related age-related change.change.

Other Other NeurNeurotransmitotransmitters.ters. The The neurotransmitterneurotransmitter serotonin serotonin is is involved involved in in sevseveral eral types types of of brain brain processes,processes, including including memorymemory, , mood, mood, appetite, appetite, and and sleep. sleep. AbnorAbnor-- mal mal processing processing of of serotonin serotonin has has been been shoshown wn to to be be relatedrelated to to cognitive cognitive decline decline both both in in normative normative aging aging and and inin dementia dementia (such (such as as AlzheimerAlzheimer’’s s disease), disease), as as well well as as otherother disorders disorders such such as as sleep sleep problems problems and and schizschizophreniaophrenia (M(McCarthycCarthy, , 2021; 2021; Rodriguez Rodriguez et et al., al., 2012; 2012; Štrac Štrac et et al.,al., 2016). 2016). IncrIncreasing easing the the functional functional level level of of serotoninserotonin has has beneficial beneficial effects effects for for certain certain problems problems (McCarthy(McCarthy,, 2021; 2021; ŠŠtrac trac et et al., al., 2016). 2016). In In Chapter Chapter 10, 10, we we will will rreturneturn to to the the role role of of serotonin serotonin in in mental mental disordisorders.ders.

processes processes that that are are mormore e automatic automatic and and less less effortful. effortful. (The(The distinctions distinctions between between these these are are explorexplored ed in in more more detaildetail in in Chapter Chapter 6.) 6.) TTo o investigate investigate dopamine, dopamine, most most studies studies have have used used postmortem postmortem analyses analyses (i.e., (i.e., analyses analyses duringduring autopsies), autopsies), results results from from neuropsyneuropsychological chological tests, tests, simulatedsimulated modeling, modeling, and and the the imaging imaging of of dopamine dopamine activityactivity.. Researchers Researchers (Karalija (Karalija et et al., al., 2021; 2021; MMatherather, , 2016; 2016; PPark ark && FFestini, estini, 2017) 2017) have have concluded concluded that that there there is is clear clear evidenceevidence that that effective effective functionifunctioning ng of of the the dopaminergic dopaminergic systemsystem is is critical critical for for cognitive cognitive processes, processes, and and that that it it declines declines inin typical typical aging. aging. Exactly Exactly what what does does this this mean?mean?

Declines Declines in in the the dopadopaminergic minergic system system arare e related related toto declines declines in in several several different different aspects aspects of of memory memory (Karalija(Karalija et et al., al., 2021; 2021; NNevalainen evalainen et et al., al., 2015; 2015; Yin Yin & & WWang, ang, 2016), 2016), such such as as episodic episodic memory memory and and memormemory y for for inforinfor-- mation mation acquired acquired in in tasks tasks that that must must be be performedperformed quicklyquickly, , and and the the amount amount of of information information that that can can bebe held held in in mind mind at at any any given given moment moment (called (called workingworking memory). memory). As As we we will will explore explore in in Chapter Chapter 6, 6, these these areare cognitive cognitive tasks tasks that that requirrequire e cognitive cognitive effort. effort. In In contrast,contrast,

Figure Figure 2.4 2.4 Association Association between between the the disruption disruption to to the the dordorsal sal attention attention networknetwork (DAN) (DAN) and and falls falls risk risk (PP(PPA A score) score) as as a a function function of of activity activity levellevel The The association association between between the the disrdisruption uption to to the the dorsal dorsal atattention tention netnetwork work (D(DAN) AN) and and falls falls risk risk (PP(PPAA score) score) is is moderated moderated by by phphysical ysical activity activity levlevel. el. Higher Higher phyphysical sical activity activity score score for for the the elderly elderly (P(PASE)ASE) lowlowered ered the the association association between between greater greater disruption disruption to to the the DDAN AN and and higher higher PPPPA A score.score.

Source: Source: CrocCrocketkett, t, R. R. A., A., Hsu, Hsu, C. C. L., L., Dao, Dao, E., E., TTam, am, R., R., AlkeridyAlkeridy, , A., A., Eng, Eng, J. J. JJ., ., HandyHandy, , TT. . C., C., && Liu-Ambrose, Liu-Ambrose, TT. . (2022). (2022). Mind Mind the the gaps: gaps: FFunctional unctional networks networks disrupted disrupted by by white white matmatter ter hyperintenhyperintensitsitieiess are are associated associated with with greater greater falls falls risk. risk. Neurobiology Neurobiology of of Aging, Aging, 1109, 09, 1166–166–175. 75. hthttps://doi.org/1tps://doi.org/10.10.100116/j6/j .neurobiolaging.2021.neurobiolaging.2021.09.023. .09.023. Figure Figure 4.4.

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Copyright Copyright 2024 2024 Cengage Cengage Learning. Learning. All All Rights Rights Reserved. Reserved. May May not not be be copied, copied, scanned, scanned, or or duplicated, duplicated, in in whole whole or or in in part. part. Due Due to to electronic electronic rights, rights, some some third third parparty ty content content may may be be suppressed suppressed from from the the eBook eBook and/or and/or eChapter(s).eChapter(s).

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46 46 Chapter Chapter 2 2 | | Neuroscience Neuroscience as as a a Basis Basis for for Adult Adult Development Development and and AgingAging

it it is is the the link link between between brain brain structurstructures es and and functionsfunctions and and our our behavior behavior that that matters. matters. LetLet’’s s consider consider a a few few that that are are particularly particularly important. important. What What we we will will discodiscover ver is is thethe truly truly central central role role played played by by the the prefrprefrontal ontal cortex, cortex, thethe last last area area in in the the brain brain to to fully fully develop develop chronologicallychronologically,, usually usually not not until until a a personperson’’s s late late 20s.20s.

There There is is no no question question that that neuroscience neuroscience rresearchesearch points points to to the the central central role role played played by by the the prprefrontal efrontal cortexcortex in in adult adult development development and and aging. aging. This This part part of of the the brainbrain is is intimately intimately involved involved in in the the most most important important aspectsaspects of of thinking thinking and and reasoning, reasoning, including including executivexecutive e funcfunc-- tioning, tioning, decision decision making, making, memorymemory, , and and emotion. emotion. So So itit is is probably probably not not surprising surprising to to discovdiscover er that that at at a a detaileddetailed level, level, age-related age-related changes changes in in the the prprefrontal efrontal cortex cortex areare complex.complex.

The The most most important important arena arena in in this this complex complex patternpattern is is in in the the interface interface between between emotion emotion and and memorymemory. . AnAn intriguing intriguing research research finding finding is is that that brain brain pathwayspathways involved involved in in memory memory tend tend to to deteriorate deteriorate with with age,age, whereas whereas key key pathpathways ways involved involved in in emoemotion tion do do not.not. HoHow w is is this this explained?explained?

Let’Let’s s start start by by focusing focusing on on a a well-documented well-documented effecteffect called called the the positivity positivity effect.effect.The The positivity positivity effeffect ect referreferss to to the the fact fact that that older older adults adults are are often often more more motivatedmotivated to to derive derive emotional emotional meaning meaning from from life life and and to to mainmain-- tain tain positive positive feelingsfeelings (Isaaco(Isaacowitz witz & & Blanchard-FBlanchard-Fields, ields, 2012; 2012; Kensinger Kensinger & & Gutchess, Gutchess, 2017; 2017; PPetro etro et et al.,al., 2021). 2021). As As a a result, result, older older adults adults are are mormore e likely likely thanthan younger younger adults adults to to attend attend to to the the emotional emotional meaning meaning ofof information.information.

Some Some of of the the brain brain pathways pathways for for processing processing bbothoth positive positive and and negative negative emotion emotion are are the the same same for for all all adultsadults

Another Another important important neurotransmitter neurotransmitter related related toto aging aging is is . . Acetylcholine Acetylcholine has has an an importantimportantacetylcholineacetylcholine role role in in general general cognitive cognitive prprocesses ocesses (arousal, (arousal, sensorysensory perception, perception, sustaining sustaining attention, attention, higher higher order order thinking)thinking) and and in in dementia dementia (Cools (Cools & & Arnsten, Arnsten, 2022; 2022; JJu u & & TTam,am, 2022) 2022) as as well well as as in in cardiocardiovascular vascular functioning functioning controlledcontrolled by by the the autonomic autonomic nervous nervous system system (discussed (discussed in in ChapterChapter 3; 3; Cools Cools & & Arnsten, Arnsten, 2022; 2022; PPascale ascale & & Govoni, Govoni, 2016).2016). Damage Damage to to brain brain structurstructures es that that use use acetylcholiacetylcholine ne isis associated associated with with serious serious memory memory declines declines such such as as thosethose found found in in Alzheimer’Alzheimer’s s disease disease and and in in the the development development ofof cardiocardiovascular vascular disease.disease.

Linking Linking StrStructuructural al Changes Changes withwith BehaviorBehavior As As you you already already knoknow w from from obserobservation vation or or personalpersonal experience, experience, our our bodies bodies undergo undergo visible visible changes changes withwith age age (such (such as as those those described described in in detail detail in in Chapter Chapter 3).3). The The brain brain is is no no exception. exception. RResearchers esearchers have have used used twotwo general general approaches approaches to to document document age-related age-related changeschanges in in brain brain structures: structures: a a correlational correlational approach approach emploemployingying postmortem postmortem and and imaging imaging analyses analyses of of adultsadults’ ’ brains,brains, and and cross-sectional cross-sectional and and longitudinal longitudinal designs designs usingusing brain brain imaging imaging techniques. techniques. In In either either approach, approach, differdifferentent regions regions of of the the brain brain are are examined examined in in terms terms of of vvariousarious structural structural changes changes and and deficiencies, deficiencies, such such as as thinthin-- ning ning and and shrinkage shrinkage in in volume volume and and densitydensity, , and and otherother changes.changes.

PPostmortem ostmortem and and neuroimaging neuroimaging studies studies verify verify thatthat many many changes changes occur occur with with age. age. One One important important change change isis that that the the brain brain shrinks, shrinks, or or atrophies, atrophies, by by late late life, life, genergener-- ally ally shrinking shrinking about about 5% 5% per per decade decade starting starting around around ageage 40 40 and and perhaps perhaps increasing increasing after after age age 70 70 in in most most people.people. The The cerebral cerebral cortex cortex gets gets thinner thinner ovover er this this same same timetime span. span. The The ventricles ventricles (structures (structures that that look look like like openopen spaces) spaces) increase increase in in size.size.

HoHoweverwever, , these these structural structural changes changes are are not not uniformuniform across across the the whole whole brain brain (Pini (Pini et et al., al., 2016). 2016). FFor or example,example, the the prefrprefrontal ontal cortex, cortex, the the hippocampus, hippocampus, and and thethe cere cere-- bellum bellum show show more more significant significant atratrophyophy. . In In contrast, contrast, thethe areas areas of of the the brabrain in related related to to sensosensory ry functions, functions, such such asas the the visual visual cortex, cortex, showshow relatively relatively little little atratrophyophy. . TheseThese differential differential patterns patterns map map to to different different rates rates of of changechange in in behavior behavior and and underlying underlying abilities abilities and and can can be be usedused to to track track the the difference difference between between normativnormative e changes changes andand changes changes associated associated with with disease.disease.

IIt t is is easy easy enough enough to to focus focus on on the the structural,structural, anatomical anatomical changes changes that that occur occur in in peoplepeople’’s s brains brains as as theythey age age through through adulthood. adulthood. But But what what do do these these changeschanges really really imply imply in in a a personperson’’s s evereveryday yday life? life? FFor or most most of of us,us,

What What eaceach h perperson son in in this this couple couple eventually eventually remembersremembers about about their their relationship relationship is is likely likely to to include include more more positipositive ve thanthan negative negative memories memories due due to to the the positivity positivity effect.effect.

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Neuroscience Neuroscience and and the the Aging Aging Brain Brain 4747

cortex, cortex, in in combination combination with with other other key key brain brain structures,structures, and and find find out out what’what’s s going going on on as as people people age.age.

StrStructural uctural ChangChanges, es, Theory Theory of of Mind, Mind, and and ExExecuecu-- tive tive FFunctions.unctions. One One of of the the most most important important abilitiesabilities we we have have is is to to interprinterpret et oneone’’s s own own and and othersothers’ ’ mentalmental and and emotional emotional states.states.This This abilityability, , termed termed theory theory ofof mind mind (T(ToM)oM), , helps helps us us understand understand that that other other peoplepeople have have beliefs, beliefs, desires, desires, ideas, ideas, feelings, feelings, intentions, intentions, andand viewpoints viewpoints that that are are difdifferent ferent from from our our own.own. OOnnee’s’s TToM oM develops develops across across the the life life span span and and is is a a crucial crucial aspectaspect of of social social cognition, cognition, as as we we will will consider consider in in Chapter Chapter 8.8. Because Because of of its its central central role role in in everyday everyday life, life, TToM oM is is oneone benchmark benchmark by by which which to to determine determine whether whether an an indiindi-- vidual vidual demonstrates demonstrates a a developmental developmental or or cognitivecognitive impairment impairment (Healey (Healey & & GGrossmarossman, n, 2016; 2016; LagattutaLagattuta et et al., al., 2016; 2016; Rosi Rosi et et al., al., 2016).2016).

In In briefbrief, , TToM oM matters matters a a great great deal deal in in everydayeveryday life. life. FFor or instance, instance, TToM oM is is involved involved in in peoplepeople’’s s sense sense ofof empathy empathy and and in in emotional emotional intelligence, intelligence, characteristicscharacteristics that that help help us us understand understand another another personperson’’s s experienceexperience and and point point of of viewview. . Research Research indicates indicates that that TToM oM abilitiesabilities increase increase during during childhood childhood and and show show some some age-rage-relatedelated decline decline in in adults adults over over age age 75. 75. LetLet’’s s go go a a bit bit deeper deeper toto consider consider the the underlying underlying changes changes in in the the brain brain that that mightmight explain explain the the TToM oM changes changes in in later later life.life.

UUnderstanding nderstanding how how changes changes in in brain brain structuresstructures affect affect behavior behavior invinvolves olves carefcareful ul linking linking of of specific specific brainbrain structures structures to to specific specific behaviors, behaviors, as as we we have have discodiscovered.vered. FFirst, irst, it it is is necessarnecessary y to to carefully carefully describe describe the the behaviorbehavior that that interests interests us. us. Second, Second, carcareful eful documentation documentation ofof structural structural changes changes in in the the brain brain is is nenecessarycessary. . Third, Third, thethe two two sets sets of of data data need need to to be be connected connected to to establish establish thethe link link between between structural structural brain brain changes changes and and behaviorbehavior..

regarregardless dless of of age. age. SpecificallySpecifically, , the the common common pathwayspathways in in emotion emotion processing processing for for adults adults of of all all ages ages include include thethe amygdala amygdala and and the the part part of of the the prefrontal prefrontal cortex cortex rightright behind behind the the eyes eyes (the (the lateral lateral orbitofrontal orbitofrontal cortex). cortex). TheThe prefrontal prefrontal cortex cortex is is especially especially involved involved in in rregulatingegulating emotions emotions (e.g., (e.g., making making sure sure that that our our emotional emotional reactionreaction is is appropriate appropriate and and fits fits the the situation). situation). The The connectionsconnections between between the the prprefrontal efrontal cortex cortex and and the the amyamygdala gdala mattermatter a a great great deal deal for for emotion emotion regulation. regulation. IIt t turns turns out out thatthat how how active active the the amygdala amygdala is is during during emotion emotion prprocessingocessing appears appears particularly particularly important. important. In In certain certain people people whowho have have intermittent intermittent explosive explosive disordisorder der (i.e., (i.e., becomebecome extremely extremely angry angry when when shown shown angry angry faces, faces, for for instance),instance), the the amygdala amygdala shows shows hyperactivation hyperactivation (M(McCloskey cCloskey et et al.,al., 2016), 2016), which which may may be be the the cause cause of of the the disorderdisorder..

ResearResearch ch also also indicates indicates that that in in additiaddition on to to somesome common common brain brain areas areas that that process process all all emotion, emotion, thertheree are are also also some some unique unique pathways. pathways. FFor or instance, instance, positivepositive emotional emotional processing processing occurs occurs in in the the front front section section ofof the the prefrontal prefrontal cortex. cortex. FFor or negative negative emotion emotion processing,processing, the the temporal temporal (side) (side) region region is is brought brought into into action action instead.instead.

But But there there arare e some some imporimportant tant age-related age-related differdiffer-- ences ences in in brain brain pathways, pathways, too, too, that that help help us us understandunderstand age-related age-related differences differences in in emotion-remotion-related elated behaviors.behaviors. When When older older adults adults process process information information that that is is emotionemotion-- ally ally positive, positive, they they have have increased increased activity activity in in the the middlemiddle portion portion of of the the prefrontal prefrontal cortex, cortex, the the amygdala, amygdala, andand the the cingulate cingulate cortex cortex (a (a structure structure that that forms forms a a ““collarcollar”” around around the the corpus corpus calloscallosum). um). YYounger ounger adults adults do do notnot have have this this pattern. pattern. Bringing Bringing additional additional arareas eas of of the the brainbrain into into play play during during emotion emotion processing processing is is an an age-relatedage-related phenomenon phenomenon that that matters matters and and explains explains much much aboutabout why why older older and and young young adults adults differ differ in in how how they they rreact eact toto emotional emotional content content and and situations, situations, a a point point we we will will returnreturn to to a a bit bit laterlater..

These These age-related age-related changes changes in in how how the the brainbrain processes processes positive positive and and negative negative emotional emotional informainforma-- tion tion indicate indicate both both that that there there are are prprobably obably underlyingunderlying structural structural changes changes in in the the brain brain that that rresult esult in in age-related age-related differences differences inin behavior behavior, , and and that that these these structuralstructural changes changes can can be be quite quite nuancenuanced d and and complex. complex. AdAdditiondition-- allyally, , neuroimaging neuroimaging research research has has drawn drawn attention attention to to thethe truly truly central central and and critical critical role role played played by by the the prefrprefrontalontal cortex cortex in in understanding understanding why why people people arare e the the way way theythey are are and and process process information information in in the the ways ways they they do do (G(Gradyrady et et al., al., 2016). 2016). Changes Changes in in how how the the prefrprefrontal ontal cortex cortex isis connected connected with with other other parts parts of of the the brain brain have have importantimportant implications implications for for behaviorbehavior, , as as we we will will encounter encounter at at severalseveral other other points points in in this this book. book. Because Because it it is is so so important, important, let’let’ss make make a a closer closer examination examination of of the the role role of of the the prefrprefrontalontal

Knowing Knowing what what another another person person is is thinking thinking and and feeling feeling reflects reflects aa theory theory of of mind.mind.

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48 48 Chapter Chapter 2 2 | | Neuroscience Neuroscience as as a a Basis Basis for for Adult Adult Development Development and and AgingAging

(Reuter-Lor(Reuter-Lorenz enz et et al., al., 2021). 2021). This This ““disconnected disconnected brainbrain”” hypothesis hypothesis (Coelho (Coelho et et al., al., 2021; 2021; Fjell Fjell et et al., al., 2017)2017) underlies underlies contemporary contemporary theories theories explaining explaining much much ofof the the cognitive cognitive decline decline in in older older adults.adults.

StrStructural uctural ChangChanges es and and MemoryMemory.. A A great great deal deal ofof research research has has examined examined links links between between memory memory andand specific specific structural structural changes changes in in the the brain brain (Rudy(Rudy, , 2020).2020). Many Many areas areas in in the the brain brain arare e intimately intimately involved involved in in thethe creation, creation, storage, storage, and and rretrieval etrieval of of memories. memories. Among Among thethe most most important important are are the the frontal, frontal, temporal, temporal, and and parietalparietal lobes; lobes; hippocampus; hippocampus; amygdala; amygdala; and and cerebellum. cerebellum. In In thisthis section, section, wewe’ll ’ll focus focus on on the the temporal temporal lobe lobe and and one one of of itsits key key structures, structures, the the hippocampus.hippocampus.

The The temporal temporal lobe, lobe, highlighted highlighted in in FFigure igure 2.5, 2.5, is is thethe heart heart of of memormemory y processing, processing, having having involvement involvement withwith

One One areaarea in in which which this this type type of of carcareful eful researresearchch has has been been done done concerns concerns executive executive functioning, functioning, the the setset of of skills skills that that underlies underlies TToM oM (Roca, (Roca, 2016). 2016). ExecutiveExecutive function function skills skills arare e the the mental mental processprocesses es that that enable enable usus to to plan, plan, focus focus attention, attention, remember remember instructions, instructions, andand juggle juggle multiple multiple tasks tasks successfullysuccessfully.. They They rely rely on on threethree important important brain brain functions: functions: working working memory memory (our(our ability ability to to retain retain and and manipulate manipulate distinct distinct pieces pieces of of inforinfor-- mation mation over over short short periods periods of of time), time), mental mental flexibilityflexibility (our (our ability ability to to sustain sustain or or sshift hift attention attention in in rresponseesponse to to different different demands demands or or to to apply apply different different rules rules inin different different settings), settings), and and self-control self-control (our (our ability ability to to setset priorities priorities and and resist resist impulsive impulsive actions actions or or rresponses).esponses). ExecutivExecutive e function function skills skills develop develop from from childhoodchildhood through through emerging emerging adulthood adulthood (the (the late late 20s) 20s) as as the the brainbrain continues continues to to mature mature and and completes completes its its creation creation of of majormajor interconnections.interconnections.

EEvidence vidence indicates indicates that that some some executive executive functionfunction skills skills decline decline in in later later life. life. ExecutivExecutive e functioning functioning failuresfailures in in older older adults adults can can result result in in such such behaviors behaviors as as the the errerroo-- neous neous selection selection of of irrelevant irrelevant infinformation ormation as as rrelevant,elevant, the the inability inability to to divert divert attention attention away away from from irrelevantirrelevant information information to to the the task task at at hand, hand, and and inefficiency inefficiency inin switching switching tasks, tasks, among among others. others. These These changes changes matter;matter; mortality mortality rates rates are are higher higher in in those those showing showing the the mostmost decline decline (Aron (Aron et et al., al., 2022; 2022; Baggetta Baggetta & & AlexanderAlexander, , 2016;2016; WWu u et et al., al., 2020). 2020). FFor or example, example, consider consider a a task task in in whichwhich one one must must distinguish distinguish true true and and false false information, information, suchsuch as as identifying identifying an an actual actual email email from from a a phishing phishing email.email. When When older older adults adults are are reading reading an an email email that that is is filledfilled with with information, information, some some of of which which is is true true and and some some ofof which which is is false, false, even even if if they they are are told told which which informationinformation is is false, false, they they still still have have a a difficult difficult time time ignoring ignoring the the falsefalse information information in in their their understanding understanding of of the the email.email.

HoHow w is is this this connected connected to to changes changes in in the the brain? brain? PPooroor performance performance on on executive executive functioning functioning tasks tasks has has beenbeen linked linked to to decreased decreased volume volume of of the the prprefrontal efrontal cortexcortex (M(McEcEwen wen et et al., al., 2016; 2016; Reuter-LorReuter-Lorenz enz et et al., al., 2021).2021). EEvidence vidence also also suggests suggests that that WMH WMH in in healthy healthy olderolder adults adults who who shoshow w no no signs signs of of serious serious cognitivcognitive e diseasedisease (such (such as as dementia) dementia) have have been been linked linked to to lowlower er cognicogni-- tive tive performance performance and and decreased decreased executivexecutive e functioningfunctioning (Coelho (Coelho et et al., al., 2021). 2021). Age-related Age-related decline decline in in the the funcfunc-- tioning tioning of of blood blood vessels vessels in in the the brain brain may may affect affect whitewhite matter matter structures structures that that underlie underlie all all the the areas areas importantimportant to to executive executive functioning.functioning.

Whatever Whatever the the cause, cause, evidence evidence is is mounting mounting thatthat decline decline in in executive executive functioning functioning with with age age is is relatedrelated to to the the degeneration degeneration and and disruption disruption of of connectionsconnections among among various various regions regions and and structures structures of of the the brainbrain

Figure Figure 2.5 2.5 The The structures structures in in the the temporal temporal lobe lobe play play kkey ey roles roles inin the the creation creation of of memorymemory

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Brain Brain stemstem CerCerebellumebellum

Occipital Occipital lobelobe

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Neuroscience Neuroscience and and the the Aging Aging Brain Brain 4949

StrStructural uctural ChangChanges es in in Emotional Emotional MemoryMemory.. As As wewe have have noted noted earlierearlier, , the the age-related age-related changes changes obserobserved ved inin executive executive functioning functioning and and memory memory map map onto onto age-related age-related deterioration deterioration in in specific specific brain brain structures. structures. LetLet’’s s now now gogo deeper deeper to to consider consider a a very very important important aspect aspect of of the the humanhuman experience—emotion experience—emotion and and memory—and memory—and explore explore howhow structural structural brain brain changes changes affect affect it.it.

TTo o begin, begin, let’let’s s consider consider an an example example of of hohow w neuroneuro-- imaging imaging research research helps helps establish establish linkages linkages between between brainbrain structures structures (the (the prefrontal prefrontal cortex cortex and and the the amygdala) amygdala) andand behavior behavior relating relating to to emotion. emotion. An An excellent excellent example example ofof how how this this researresearch ch is is done done is is a a groundbreaking groundbreaking study study bbyy Winecoff Winecoff and and colleagues colleagues (2011). (2011). They They administered administered aa large large battery battery of of tests tests to to measure measure cognitive cognitive performanceperformance and and emotional emotional behavior behavior to to younger younger adults adults (average(average age age = = 23 23 years, years, range range = = 19–33 19–33 years) years) and and older older adultsadults (average (average age age = = 69 69 years; years; range range = = 59–73 59–73 years). years). AfterAfter these these measures measures werwere e obtained, obtained, participants participants were were givengiven a a cognitive cognitive rreappraisal eappraisal task. task. DDuring uring the the experiment,experiment, participants participants learned learned a a reappraisal reappraisal strategy strategy that that involvedinvolved thinking thinking of of themselves themselves as as an an emotionally emotionally detached detached andand objective objective third third partyparty. . During During the the training training session, session, theythey told told the the experimenter experimenter how how they they werwere e thinking thinking aboutabout the the image image to to ensure ensure ttask ask compliance, compliance, but but they they werweree instructed instructed not not to to speak speak during during the the fMRI fMRI scanningscanning session session that that provided provided images images of of ongoing ongoing brain brain activityactivity..

YYounger ounger and and older older adults adults performed performed the the reappraisalreappraisal tasks tasks similarly; similarly; that that is, is, in in the the rreappraisal eappraisal condition,condition, positive positive images images were were rreporeported ted as as less less positive positive and and neganega-- tive tive images images were were rreporeported ted as as less less negative. negative. HHowevoweverer,, older older adultsadults’ ’ reports reports of of negative negative emotion emotion were were higherhigher than than those those of of younger younger adults adults in in the the negative negative reappraisalreappraisal situation.situation.

Winecoff Winecoff and and colleagucolleagueses’ ’ (2011) (2011) breakthroughbreakthrough was was that that examination examination of of the the fMRI fMRI results results showshowed ed thatthat reappraisals reappraisals invinvolved olved significant significant activaactivation tion of of specificspecific areas areas in in the the prefrprefrontal ontal cortex cortex for for both both positive positive andand negative negative emotions. emotions. FFor or both both age age groups, groups, activity activity in in thethe prefrontal prefrontal ararea ea increased, increased, and and activity activity in in the the amygdalaamygdala decreased decreased during during the the reappraisal reappraisal phase. phase. These These patternspatterns are are noted noted in in FFigure igure 2.6. 2.6. AAs s documented documented in in the the toptop figure, figure, certain certain areas areas in in the the prefrprefrontal ontal cortex cortex showedshowed a a pattern pattern of of activation activation that that followfollowed ed participantsparticipants’’ self-reports self-reports of of emotion emotion regulation. regulation. Depicted Depicted herheree are are activation activation patterns patterns in in the the contrast contrast betweenbetween “Reappraise-N“Reappraise-Negativeegative” ” and and “Experience-N“Experience-Negative”egative” conditions. conditions. The The graph graph notes notes that that for for both both positive positive andand negative negative stimuli, stimuli, and and for for both both younger younger and and older older adults,adults, prefrontal prefrontal activactivation ation increased increased in in “R“Reappraiseeappraise” ” (reap)(reap) trials trials compared compared to to “Experience“Experience” ” (exp) (exp) trials. trials. In In contrast,contrast,

each each step step of of getting getting information information in in (encoding), (encoding), consoliconsoli-- dating dating it, it, and and getting getting it it back back out out (retrieval). (retrieval). The The medialmedial temporal temporal lobe lobe includes includes the the hippocampus, hippocampus, amygdala,amygdala, and and nearby nearby support support structures structures and and is is crucial crucial forfor episodic episodic (time-stamped) (time-stamped) and and spatial spatial memorymemory, , as as wellwell as as the the memory–emotion memory–emotion connection. connection. Damage Damage to to thethe medial medial temporal temporal lobe lobe can can result result in in serious serious and and permaperma-- nent nent loss loss of of event-based event-based and and time-stamped time-stamped memories, memories, including including aspects aspects of of a a personperson’’s s autobiographyautobiography. . AsAs individuals individuals age, age, the the medial medial temporal temporal lobe lobe shrinksshrinks normativelynormatively, , but but this this shrinkageshrinkage is is markedly markedly incrincreasedeased in in certain certain disease, disease, such such as as Alzheimer’Alzheimer’s s disease, disease, whichwhich helps helps explain explain why why severe severe memory memory loss loss is is one one hallmarkhallmark of of this this disorderdisorder..

Considerable Considerable research research has has focused focused on on the the centralcentral involvement involvement of of the the hippocampus hippocampus in in memory memory (Brunec(Brunec et et al., al., 2020). 2020). FFor or example, example, the the hippocampus hippocampus is is believedbelieved to to be be the the brain brain location location where where related related experiences experiences oror incoming incoming information information are are integrated integrated into into a a personperson’’ss existing existing knowledge knowledge base. base. SSeveral everal lines lines of of inquiry inquiry have have supported supported this this notion. notion. One One involves involves the the basicbasic neuroscience neuroscience understanding understanding of of how how the the hippocampus hippocampus isis involved involved in in ((creates) creates) memorymemory. . FFrom rom this this approach, approach, wewe knowknow, , for for example, example, that that the the hippocampus hippocampus is is inintimatelytimately involved involved in in such such types types of of memory memory as as autobiographicalautobiographical memory memory (remembering (remembering aspects aspects of of our our lives; lives; GurguryanGurguryan et et al., al., 2021; 2021; Sheldon Sheldon & & Levine, Levine, 2016) 2016) and and recognizingrecognizing patterns patterns (Brunec (Brunec et et al., al., 2020).2020).

A A second second approach approach involves involves examining examining structuralstructural changes changes to to the the hippocampus hippocampus in in diseases diseases such such as as mildmild cognitive cognitive impairment impairment and and AlzheimerAlzheimer’’s s disease disease (Goukasian (Goukasian et et al., al., 2019) 2019) and and chronic chronic high high levels levels of of strstress ess (McE(McEwen,wen, 2017; 2017; WWoo oo et et al., al., 2018) 2018) tthat hat produce produce negativnegative e impactsimpacts on on memorymemory. . The The stress stress connection connection is is crucial—ascrucial—as discussed discussed in in Chapter Chapter 4, 4, stress stress comes comes from from many many sources,sources, including including sociocultural sociocultural factors factors such such as as system system disparidispari-- ties ties and and discrimination. discrimination. IntriguinglyIntriguingly, , evidence evidence suggestssuggests that that intellectual intellectual stimulation stimulation in in earlier earlier adulthood adulthood (such(such as as reading) reading) helps helps incrincrease ease the the size size of of the the hippocampus,hippocampus, which which may may provide provide some some prprotection otection against against memorymemory decline decline associated associated with with certain certain diseases diseases (Sumo(Sumowskiwski et et al., al., 2016).2016).

In In each each of of these these cases, cases, deterioration deterioration of of the the specificspecific brain brain structure(s) structure(s) due due to to normative normative age-relatedage-related processes, processes, disease, disease, or or injury injury results results in in a a significantsignificant deficit deficit in in memory memory and and related related cognitive cognitive abilities abilities (R(Rudyudy,, 2020). 2020). In In ororder der to to understand understand how how these these complexcomplex systems systems work work and and are are connected connected and and integrated, integrated, we we willwill return return to to the the case case of of memory memory and and emotion emotion as as one one keykey system system that that shows shows marked marked age-rage-related elated changes.changes.

50 50 Chapter Chapter 2 2 | | Neuroscience Neuroscience as as a a Basis Basis for for Adult Adult Development Development and and AgingAging

roles roles in in emotion emotion regulation, regulation, but but therthere e may may be be a a neuroneuro-- logical logical explanation explanation for for the the kinds kinds of of emotional emotional behaviorbehavior outbursts outbursts that that occur occur in in dementia dementia and and related related disordisorders.ders.

SSubsequent ubsequent research research has has supported supported these these conclusionsconclusions regarregarding ding the the dynamic dynamic nature nature of of prefrprefrontal–amygdalaontal–amygdala connections connections and and their their role role in in the the modulation modulation of of emotionemotion (Berboth (Berboth & & MMorawetz, orawetz, 2021; 2021; Lemaire, Lemaire, 2022). 2022). MorMoree-- overover, , the the ability ability of of people people with with dementia dementia to to correctlycorrectly recognize recognize emotions emotions in in other other people people (their (their TToM) oM) isis impaired impaired relativrelatively ely early early in in the the disease disease (F(Fernández-Ríosernández-Ríos et et al., al., 2021); 2021); because because the the prefrontal prefrontal cortex cortex is is one one of of thethe areas areas of of the the brain brain that that shows shows the the earliest earliest deterioration deterioration in in Alzheimer’Alzheimer’s s disease, disease, these these data data also also point point out out the the crucialcrucial rorole le oof f prefrontal–amygdala prefrontal–amygdala connections.connections.

HoHow w does does the the way way that that the the brain brain processesprocesses emotions emotions change change across across adulthood? adulthood? The The quick quick answeranswer is is that that it’it’s s complicated complicated (Mather(Mather, , 2016; 2016; Ziaei Ziaei & & FFisherisher,, 2016). 2016). In In general, general, researresearch ch shows shows that that adults adults of of allall ages ages report report about about the the same same range range and and experience experience ofof emotion. emotion. But But there there is is also also evidence evidence that that changes changes inin brain brain activity activity in in the the prefrontal prefrontal cortex cortex and and the the amygdala amygdala with with age age may may be be related related to to a a differential differential decrdecrease ease inin processing processing of of negative negative emotional emotional information information andand an an increase increase in in pprocessing rocessing of of positivpositive e emotionalemotional

the the lower lower graph graph notes notes that that in in the the amygdala amygdala (amy)(amy) there there was was a a systematic systematic decrease decrease in in activactivation ation duringduring emotion emotion regulation regulation between between “Experience-N“Experience-Negativeegative” ” and and “Reappraise-N“Reappraise-Negativeegative” ” conditions.conditions.

Additional Additional analyses analyses of of the the fMRI fMRI data data indicate indicate thatthat emotion emotion regulation regulation modulates modulates the the functional functional interactioninteraction between between the the prefrontal prefrontal cortex cortex and and the the amygdala. amygdala. YYoungerounger adults adults had had more more activity activity in in the the prefrprefrontal ontal cortex cortex duringduring “Reappraise“Reappraise” ” trials trials for for negative negative pictures pictures than than older older adultsadults did. did. Cognitive Cognitive abilities abilities were were rrelated elated to to the the degree degree ofof decrease decrease in in amygdala amygdala activation, activation, independent independent of of age.age.

FFrom rom these these data , da ta , Winecoff Winecoff and and colleaguescolleagues concluded concluded that that the the prefrontal prefrontal cortex cortex plays plays a a major major rolerole in in emotional emotional regulation, regulation, especially especially for for older older adults. adults. TheThe takeaway takeaway is is the the prefrontal prefrontal cortex cortex may may help help suppresssuppress (regulate) (regulate) ememotions otions in in the the same same way way as as that that ararea ea of of thethe brain brain is is involved involved in in inhibiting inhibiting other other behaviors. behaviors. IImpormpor-- tantlytantly, , the the degree degree of of emotional emotional regulation regulation was was prpredictededicted by by cognitive cognitive abilityability, , with with higher higher cognitive cognitive ability ability assoasso-- ciated ciated with with higher higher emotional emotional regulation. regulation. This This maymay mean mean that that as as cognitive cognitive abilities abilities decline, decline, people people may may bebe less less able able to to regulate regulate their their emotionemotions, s, a a pattern pattern typicaltypical in in diseases diseases such such as as dementia. dementia. Thus, Thus, not not only only is is therethere evidence evidence of of underlying underlying brain brain structures structures playing playing criticalcritical

Figure Figure 2.6 2.6 Modulation Modulation of of prefrontal prefrontal and and amygdalar amygdalar activation activation by by emotion emotion regulationregulation Source: Source: WinecoffWinecoff, , A., A., LaBarLaBar, , K. K. S., S., Madden, Madden, DD. . J., J., Cabeza, Cabeza, R., R., & & HuetHuettel, tel, S. S. A. A. (20(20111). 1). Cognitive Cognitive and and neural neural contributions contributions to to emotion emotion regulation regulation in in aging. aging. Social Social CognitiveCognitive and and AfAffective fective Neuroscience, Neuroscience, 6.6.

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