Memory in Psy

CHAPTER 6—MEMORY

I. Introduction: Jill’s Unusually Good Memory

A. "Most have called it a gift, but I call it a burden. I run my entire life through my head every day and it drives me crazy!"

1. Memory – the ability to store and retrieve information over time

2. Encoding – the process by which we transform what we perceive, think, or feel into an enduring memory

3. Storage – the process of maintaining information in memory over time

4. Retrieval – the process of bringing to mind information that has been previously encoded and stored

II. Encoding: Transforming Perceptions into Memories

A. Bubbles P., the gambler, and his "photographic memory"

1. Memories are actually constructed, not recorded (hence, encoding)

B. Elaborative Encoding – the process of actively relating new information to knowledge that is already in memory

1. Levels of Processing – deeper processing of an item results in better memory for it later on

a. Semantic judgments vs. rhyme judgments

i. We remember the meanings of words better than how a word looks or sounds

b. visual judgments

2. Elaborative encoding is associated with increased activity in the medial part of the left temporal lobe and the ventral part of the left frontal lobe

C. Visual Imagery Encoding – the process of storing new information by converting it into mental pictures

1. Simonides’ method of visual imagery encoding equals associating an item to be remembered with a place, then taking a "mental walk" for retrieval

2. Easier to remember two items if you picture them interacting, rather than picturing them as two separate items

a. Relating the "to be remembered" item to knowledge that you already have in memory

b. Assigns two mental placeholders: visual and verbal

D. Organizational Encoding – the process of categorizing information by noticing the relationships among a series of items

1. Organizing concepts into hierarchies is one effective form of organizational encoding.

2. Within a group of items, noticing the items that are different is another effective form of organizational encoding.

3. Activates the dorsal surface of the left frontal lobe

E. Encoding of Survival-Related Information

1. Studies show that survival encoding resulted in higher levels of recall than other non- survival encoding tasks.

2. draws on elements of elaborative, imagery, and organizational encoding

3. Thinking about information with regard to its survival value might be more interesting or

emotionally arousing than other kinds of encoding.

III. Storage: Maintaining Memories over Time

A. Sensory Storage

1. Sensory Memory– holds sensory information for a few seconds or less

2. Iconic Memory – a fast-decaying store of visual information

3. Echoic Memory – a fast-decaying store of auditory information

B. Short-Term Storage and Working Memory

1. Short-Term Memory – holds nonsensory information for more than a few seconds but less than a minute

a. Short-term memory fades rapidly in accuracy and total recall

2. Rehearsal – the process of keeping information in short-term memory by mentally repeating it

3. Chunking – combining small pieces of information into larger clusters or chunks

4. Working Memory – active maintenance of information in short-term memory

C. Long-Term Storage

1. Long-Term Memory– holds information for hours, days, weeks, or years

2. Anterograde Amnesia – the inability to transfer new information from the short-term store into the long-term store

3. Retrograde Amnesia – the inability to retrieve information that was acquired before a particular date, usually the date of an injury or operation

4. The case of HM

a. Multiple daily seizures resulted in the removal of much of his temporal lobes, including the hippocampus, resulting in severe anterograde amnesia and some retrograde amnesia

b. Hippocampus is like a memory index for the cortex, gathering separate pieces of experience and integrating them into one memory; but, not the final storage site for those long-term memories

D. Memories, Neurons, and Synapses

1. Aplysia (sea slug) is useful for studying the mechanisms of memory because it has a relatively simple nervous system

2. Long-Term Potentiation (LTP) – a process whereby communication across the synapse between neurons strengthens the connection, making further communication easier

3. NMDA Receptor – a type of receptor site in the brain that influences the flow of information from one neuron to another by controlling the initiation of LTP in most hippocampal pathways

a. Work as coincidence detectors; that is, for the receptor to work, the receptor has to be bound by the neurotransmitter (glutamate) AND the postsynaptic neuron has to be excited

b. Particularly important for LTP in the hippocampus

IV. Retrieval: Bringing Memories to Mind

A. Retrieval Cues: Reinstating the Past

1. Retrieval Cue – external information that is associated with stored information and helps

bring it to mind

2. Encoding Specificity Principle – the idea that a retrieval cue can serve as an effective reminder when it helps re-create the specific way the information was initially encoded

3. State-Dependent Retrieval – the tendency for information to be better recalled when the person is in the same state during encoding and retrieval

4. Transfer-Appropriate Processing – states that memory is likely to transfer from one situation to another when the encoding context of the situations match

B. Consequences of Retrieval

1. Retrieval changes state of the memory system in important ways

2. Retrieval can improve subsequent memory

a. Retrieving information studied is different from studying information again

3. Retrieval can impair subsequent memory

a. Retrieval-Induced Forgetting – a process by which retrieving an item from long-term memory impairs subsequent recall of related items

C. Separating the Components of Retrieval

1. Left frontal lobe shows increased activity when someone attempts to retrieve previously presented information (mental effort)

2. Successfully remembering the past is associated with activation of the hippocampal region as well as sensory regions of the brain associated with the memory

V. Multiple Forms of Memory: How the Past Returns

A. Explicit and Implicit Memory

1. Explicit Memory – the act of consciously or intentionally retrieving past experiences

2. Implicit Memory – the influence of past experiences on later behavior and performance, even though people are not trying to recollect them and are not aware that they are remembering them

a. Procedural Memory – the gradual acquisition of skills as a result of practice, or “knowing how” to do things

b. Priming – an enhanced ability to think of a stimulus, such as a word or object, as a result of a recent exposure to the stimulus

i. perceptual priming

ii. conceptual priming

c. People who lose memories of personal experiences often retain procedural memories and priming

B. Semantic and Episodic Memory

1. Semantic Memory – a network of associated facts and concepts that make up our general knowledge of the world

2. Episodic Memory and Imagining the Future

a. Episodic Memory – the collection of past personal experiences that occurred at a particular time and place

i. Form of memory that allows us to engage in “mental time travel”

3. Do Animals Have Episodic Memory?

Nonhuman animals exhibit behaviors that suggest they have episodic memory, but it is

a. hard to know what they “feel” when the information “comes to mind”.

VI. Memory Failures: The Seven Sins of Memory

A. Transience – forgetting what occurs with the passage of time

1. Occurs during the storage phase, after encoding and before retrieval

2. The Curve of Forgetting – rapid decline of savings from the time since the original learning that levels off and remains relatively stable after several hours or a day

3. Retroactive Interference – situations in which later learning impairs memory for information acquired earlier

4. Proactive Interference – situations in which earlier learning impairs memory for information acquired later

B. Absentmindedness – a lapse in attention that results in memory failure

1. Happens most often when attention is divided between two or more items or activities (e.g., driving + cell phone conversation)

2. Less activity in lower left frontal lobe during divided attention and as activities become more automatic

3. Prospective Memory – remembering to do things in the future

a. Failures are a major source of absentmindedness

C. Blocking – a failure to retrieve information that is available in memory even though you are trying to produce it

1. Tip-of-the-Tongue Experience – the temporary inability to retrieve information that is stored in memory, accompanied by the feeling that you are on the verge of recovering the information

a. Occurs especially frequently with names

2. Name blocking is often associated with damage to the left temporal lobe on the surface of the cortex

D. Blocking – a failure to retrieve information that is available in memory even though you are trying to produce it

1. Some of the primary causes of eyewitness misidentifications

2. Source Memory – recall of when, where, and how information was acquired

3. False Recognition – a feeling of familiarity about something that has not been encountered before

4. People with frontal lobe damage are especially prone to memory misattribution errors

5. Hippocampus and many of the same cortical regions are active during correct and false recognition

a. Higher activation of previously seen or heard items in their visual and auditory cortices, respectively

6. Dangerous Misattributions

a. Kirk Bloodsworth spent 9 years in prison as the result of a misidentification; was later exonerated on DNA evidence

b. Lineup procedures have changed somewhat due to research in this area

E. Suggestibility – tendency to incorporate misleading information from external sources into personal recollections

1. Can result in complete episodes that never occurred being remembered by study subjects

2. Visual imagery and hypnosis were tools used by therapists in the early 1990s that increased suggestibility as well as the incidence of ‘recovered memories’ being reported

F. Bias – the distorting influences of present knowledge, beliefs, and feelings on recollection of previous experiences

1. Consistency Bias – reconstruction of the past to fit what we presently know or believe

2. Change Bias – exaggeration of the difference between what we feel or believe now and what we felt or believed in the past

3. Egocentric Bias – exaggeration of the change between the present and past to make ourselves look good in retrospect

G. Persistence – the intrusive recollection of events that we wish we could forget

1. Emotional experiences generally lead to more vivid and enduring recollections than nonemotional experiences

a. People with damage to their amygdala (next to the hippocampus in the temporal lobe) do not remember emotional events any better than nonemotional events

b. The amygdala initiates the release of stress-related hormones (adrenaline and cortisol) in response to an arousing event, which enhances memory for the event

2. Flashbulb Memory – detailed recollection of when and where we heard about shocking events

a. Although they are more detailed, they are not necessarily always more accurate

H. Are the Seven Sins Vices or Virtues?

1. If we remembered every event and image in our lives, no matter how much time passed, our minds would be cluttered with relatively useless details

I. The Mystery of Childhood Amnesia

1. On average, an individual’s earliest memory dates to about 3.5 years of age (3.07 for men, 3.4 for women)

2. Hard to know if these memories are precise or reconstructed from family pictures and stories

3. Recent research indicates that these early memories are more of the "known" (semantic) nature than the "recollected" (episodic) nature