Psyco

INTRODUCTION TO

PSYCHOLOGY

CLASS #9

Dr. Charles-Etienne Benoit

Today’s Lecture

 Revision of the previous classes

 I will answer any questions

Importance of Greek philosophers

 The Greeks were important because they broke loose from the

accepted religious traditions and produced what they considered

to be better stories about the origin of the world.

 They engaged in open, critical discussions of one another’s ideas

and speculated.

 A life spent thinking

Dark ages (410 – 1000)

 Greek and Roman books were lost or destroyed; little or no progress was made in

science, philosophy, or literature.

 The Christian church became increasingly powerful. Europe was dominated by mysticism,

superstition, and anti-intellectualism.

 Church dogma was no longer challengeable, it wielded tremendous power. People were

either believers or heretics, and heretics were dealt with harshly.

Islamic Golden Age

 The end of the 7th century is marked the

inauguration of the House of Wisdom in

Baghdad.

 Scholars from various parts of the world

were mandated to gather and translate

all of the world's classical knowledge into

the Arabic language.

Renaissance (1450 – 1600)

 Renaissance means “rebirth,” and during this

period, the tendency was to go back to the more

open-minded method of inquiry.

 It was a time when Europe gradually switched from

being God-centered to being human-centered.

 If God existed, he existed in nature; therefore, to

study nature was to study God.

Florence, Italy

When science challenge dogma

 Born in Torun.

 Published his book De Revolutionibus

Orbium Coelestium (The Revolutions of the

Heavenly Spheres).

 Copernicus did argue successfully that,

rather than the sun revolving around the

earth (the geocentric theory), the earth

revolved around the sun (the heliocentric

theory).

 To challenge the geocentric theory was to

challenge church dogma and was therefore

heretical.

Nicolaus Copernicus

1476 – 1543

Kuyavian-Pomeranian , Poland

A period during which Western philosophy embraced the belief that unbiased reason

or the objective methods of science could reveal the principles governing the universe.

Once discovered, these principles could be used for the betterment of humankind.

The Enlightenment

 Contrast the period with the darkness of

irrationality and superstition that was

thought to characterize the Dark Ages.

 Increasing skepticism concerning

religious dogma and the Enlightenment

were closely related.

 The Enlightenment thinkers the most

important human attribute was

rationality.

Existentialism

 Existentialism: The philosophy that examines the meaning in life and stresses the

freedom that humans have to choose their own destiny. Like romanticism, existentialism

stresses subjective experience and the uniqueness of each individual.

 For the existentialists the most important aspects of humans

are their personal, subjective interpretations of life and the

choices they make in light of those interpretations.

 We can trace the origins of existential philosophy at least as

far back as Socrates, who embraced the notion of “Know

thyself” and said, “An unexamined life is not worth living”.

Rise of experimental psychology

Franz Jospeh Gall

Phrenology

Hermann Ludwig von

Helmholtz

Nerve bio-electricity

The father of psychology

 As early as 1862, Wundt performed an experiment

that led him to believe that a full-fledged discipline of

experimental psychology was possible.

Wilhelm Maximilian Wundt

1832–1920

Baden, Germany

 Wundt concluded that one

could either attend to the

position of the pendulum or

to the bell, but not both at

the same time.

 He worked as an assistant

to Hermann von Helmholtz.

Theory of evolution

 The reproductive capacity of all living organisms allows for many more offspring

than can survive in a given environment; therefore, there is a struggle for survival.

 Among the offspring of any species, there are vast individual differences, some of

which are more conducive to survival than others. This results in the survival of the

fittest.

 Thus, a natural selection occurs among the offspring of a species. This natural

selection of adaptive characteristics from the individual differences occurring among

offspring accounts for the slow transmutation of a species over the eons.

 Evolution, then, results from the natural selection of those accidental variations

among members of a species that prove to have survival value.

 Darwin defined fitness as an organism’s ability to survive and reproduce

From theory to fact

 To say the least, Darwin’s theory was revolutionary. He changed the traditional view

of human nature and with it changed the history of philosophy and psychology.

 In general, Darwin stimulated interest in the study of individual differences and

showed that studying behavior is at least as important as studying the mind.

Darwin’s tree of life, 1859

 His direct comparison of humans with

other animals, along with his forceful

assertion that humans differ from other

animals only in degree, launched

modern comparative and animal

psychology.

 It became clear that much could be

learned about humans by studying

nonhuman animals.

Conditioned Reflex

 During his work on digestion, Pavlov

discovered the conditioned reflex (or

learned reflex).

 While studying the secretion of gastric

juices in response to food (e.g., meat

powder), he noticed that events

associated also caused stomach

secretions.

 For example, the mere sight of the

experimenter or the sound of the

footsteps.

Mental illness

 Although the condition we now refer to as mental illness has

existed from at least the beginning of recorded history, when

the behavior and thought processes thought to characterize

mental illness are examined, several recurring themes become

evident.

 Harmful behavior

 Unrealistic thoughts and perception

 Inappropriate emotions

 Unpredictable behaviors

Definition: psychoanalysis

 A therapeutic method originated by Freud for treating disorders of the

personality or behaviour by bringing into a patient’s consciousness his

unconscious conflicts and fantasies (which are attributed chiefly to the

development of the sexual instinct) through the free association of ideas,

analysis and interpretation of dreams and parapraxes, etc., and

allowing him to relive them by transference.

 A theory of personality and psychical life derived from this, based on

concepts of the ego, id, and super-ego, the conscious, pre-conscious, and

unconscious levels of the mind, and the repression of the sexual instinct;

more widely, a branch of psychology dealing with the unconscious.

Oxford English Dictionary

The nervous system

 The nervous system is generally divided

into two main parts.

 The central nervous system includes the

brain and spinal cord.

 The peripheral nervous system, comprising

the sensory and motor nerves and

associated nerve cell ganglia (groups of

neuronal cell bodies), is located outside

the central nervous system.

Synapse

 Synapses are specialized regions that

permit chemical or electrical signaling

between neurons.

 The nerve cell transmitting a signal is

called the presynaptic cell; the cell

receiving the signal is the postsynaptic cell.

 Information is transferred across synapses

from one neuron to the next, or from a

neuron to a non-neuronal cell such as those

in muscles or glands.

Blood-brain barrier

 The BBB limits which materials in the

blood can gain access to neurons in the

nervous system.

 Astrocytes ensheath small arterioles

and capillaries throughout the brain.

 The barrier is largely the result of

tight junctions between endothelial

cells and cerebral capillaries, a

feature not shared by capillaries in

other parts of the body.

Glia insulating the axons

 Insulate: to separate from conducting bodies by means of nonconductors so as to

prevent transfer of electricity.

 To increase the speed by which the electricity is conducted in axons.

 This happen because they are wrapped in an insulating sheath of a lipid

substance, myelin.

In the CNS In the PNS

Recording of action potential

 Their discovered the

basis for propagation

of nerve impulses.

 They made their

discovery from the

giant axon of the

Atlantic squid.

 This discovery earned

them the Nobel Prize in

Physiology or Medicine

in 1963.

Andrew Huxley

1917 – 2012

London, England

Alan Hodgkin

1914 – 1998

Oxfordshire, England

Giant atlantic squid

 Its axon is the largest

axon known to science.

 They have a diameter

of 1 mm.

Action potential

 Voltage-gated ion channels located in the spike-triggering zone at the axon

hillock, and along the extent to the axon, open and close rapidly, changing

their conductance to specific ions and resulting in the action potential.

 The time course of changes in membrane voltage during an action potential,

and the underlying causative changes in membrane conductance to Na+

(gNa) and K+ (gK).

Share processing

 Each system begins with anatomical

structures for collecting, filtering,

and amplifying information from

the environment.

 They have specialized receptor cells

that transduce the environmental

stimulus into neural signals.

Anatomy of senses

 These neural signals are

passed along their

specific sensory nerve

pathways and travel up

the spinal cord and

enter the brain to

terminate in different

parts of the thalamus.

Thalamus

 The thalamus is a large mass of gray matter in the dorsal part of the

diencephalon of the brain with several functions such as relaying of sensory

signals to the cerebral cortex, but also the regulation of consciousness, sleep,

and alertness.

Somatosensory map

Cortical volume changes with

mechanoreceptor density

variation across skin regions

(so-called “homunculus”)

Homunculus

This model shows what a man's

body would look like if each

part grew in proportion to the

area of the cortex of the

brain concerned with its

sensory perception.

Electromagnetic radiation

Visual photoreceptors

Human perception of colors results from the simultaneous activation of

different classes of photoreceptors in the retina.

(Vuilleumier 2015)

Choose your music carefully

Range of emotions

Epigenetics

 Epigenetics represents the science

for the studying heritable changes

of DNA, not involving changes in

DNA sequence, that regulate gene

expression.

 Research on the changes in a

chromosome without alterations in

the DNA sequence

 Histone modifications

 DNA methylation

Epigenetic effects

Familial risk of psychiatric disorders

 Correlations between monozygotic twins for psychiatric disorders are

considerably greater than those between dizygotic wins.

 The risk of developing schizophrenia is greater in close relatives of a

schizophrenic patient.

Familial risk of other disorders

 Comparing Identical and

Fraternal Twins: A higher

percentage of disease

incidence in both identical

twins is the first indication

of a genetic component.

 Percentages lower than

100% in identical twins

indicates that DNA alone

does not determine

susceptibility to disease.

Epigenetic differences arise during the lifetime of monozygotic twins

Wong, et al. Human Molecular Genetics, 2005, https://doi.org/10.1093/hmg/ddi116

Autistic savant

 Savant syndrome is a condition in which someone with significant

mental disabilities demonstrates certain abilities far in excess of

average (look for Daniel Tammet).

 The skills at which savants excel are generally related to

memory. This may include rapid calculation, artistic ability, map

making, or musical ability. Usually just one special skill is present.

 Those with the condition generally have

a neurodevelopmental disorder such as autism

spectrum disorder or have a brain injury.

Kim Peek, who was the inspiration for the main character in the movie Rain Man

Stroke

 Also called apoplexy or cerebrovascular accident.

 A blockage or hemorrhage of a blood vessel leading to the brain.

Information processing model

Chunking

 A chunk is any memory pattern or meaningful unit of memory.

 By creating these chunks, a process called chunking, we can fit

more information into the seven available slots of working

memory.

 It expands working memory load

 Which is easier to remember?

4 8 3 7 9 2 5 1 6

483 792 516

Chess pieces chunking

 Chase and Simon (1973) used chess players.

 Novices – <100 hours

 Experts – >10,000 hours

Place pieces on the board (up to 24 of a middle game or random middle game) and players viewed for 5 seconds. Information in memory is stored as ‘chunks’

A chunk is a familiar pattern that can be used as a unit

Masters have about 100,000 chunks

Chunks can be recognized instantly

It takes about 10 seconds to create a chunk

Chess pieces chunking

 Information in memory is stored as

chunks (a familiar pattern that can be

used as a unit).

 Masters have about 100,000 chunks.

 They are linked to possible actions.

 In chess: identification of weaknesses,

moves, plans.

Hippocampus

 Research has found that one of

the first areas in the brain

affected by Alzheimer’s

disease is the hippocampus.

 Atrophy was correlated to the

hippocampal areas with the

presence of Alzheimer's disease.

Genetics of memory

 At the nucleus level, important nuclear

transcription factor recruit the

transcriptional machinery and initiate the

transcription of immediate early genes.

 Short-and long-term memory will lead to

the expression of numerous genes and

proteins.

Resting state

 Resting state is a method of functional magnetic resonance imaging that is

used in brain mapping to evaluate regional interactions that occur in a resting

or task-negative state, when an explicit task is not being performed.

 Five modules were identified in a functional network of the human brain,

represented by five different colors.

 Surface representation of modular architecture of a functional brain network.

Brain correlates

 Scientists still don't understand exactly how

human consciousness works.

 Magnetic resonance imaging brain scans of

coma patients (some recovered, more than half

died) and compared them with healthy

volunteers.

 The team tracked 417 different brain regions

for changes in blood flow a marker of brain

activity. They then correlated synchronized

increases or decreases in activity between

different regions.

 In healthy patients, about 40 regions lit up in

concert with many other parts of the brain.

Sleep

 The purpose of sleep is unclear.

 Restorative Hypothesis: busier we are, more sleep we need

◼ Species with higher metabolic rates typically spend more time in sleep

◼ CSF circulates during sleep to remove toxins

 Adaptive Hypothesis

 The amount of sleep depends on the availability of food and on safety

considerations.

 Vulnerable animals without shelter (cattle) and those that need to spend hours

feeding (elephants) sleep very little.

Biological clock

 Organisms from algae to people have evolved to keep time with the planet’s

light/dark beat. They do so using the world’s most important timekeepers.

 Daily, or circadian, clocks that allow organisms to schedule their days so as not to

be caught off guard by sunrise and sunset.

Mother of all clock

 A single-celled descendant

of the last universal common

ancestor (LUCA) may have

developed a primitive

circadian clock.

 The ancient timer may have

arisen in an ancestor of

animals, plants and fungi to

meet environmental

challenges, such as oxygen

toxicity.

Circadian rhythm