Memory

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OverviewReconstructing the past

The power of suggestion

In pursuit of memory

The three-box model

How we remember

Why we forget

Autobiographical memories

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The manufacture of memoryMemory is the capacity to retain and retrieve information.

Memory is a reconstructive process.

Source misattributionThe inability to distinguish what you originally experienced from what you heard or were told later about an event

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The fading flashbulb

Some unusual, shocking, or tragic events hold a special place in memory.

Called flashbulb memories because of their surprise, illumination, and photographic detail

Even flashbulb memories have errors.

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Conditions of confabulationConfabulationConfusion of an event that happened to someone else with one that happened to youA belief that you remember something when it never actually happened

Confabulation is most likely when. . .you have thought or heard about the event many times.the image of the event contains many details.the event is easy to imagine.

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The eyewitness on trial

Eyewitnesses are not always reliable

Factors influencing accuracyCross race identificationQuestion wording (e.g., “crashed” vs “hit”)Misleading information

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Children’s testimony

Under what conditions are children more suggestible?When they are very young

When interviewers’ expectations are clear

When other children’s memories for events are accessible

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Children’s testimony

When asked if a visitor committed acts that had not occurred, few 4–6 year olds said yes.100% of 3-year olds said yes.

When investigators used techniques taken from real child-abuse investigations, most children said yes.

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Explicit memory

Conscious, intentional recollection of an event or item of information.Recall: The ability to retrieve and reproduce from memory previously learned material

Recognition: The ability to identify previously encountered material

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Implicit memory

Unconscious retention in memory, as evidenced by the effect of a previous experience or previously encountered information on current thoughts or actions.

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Priming

A person reads or listens to information and is later tested to see whether the information affects performance on another type of task.

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Relearning

Compares the time required to relearn material with the time used in the initial learning of the material.

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Parallel distributed processing (PDP)

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Model of memory in which knowledge is represented as connections among thousands of interacting processing units, distributed in a vast network, and all operating in parallel

Three-box model of memory

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Sensory memory

A memory system that momentarily preserves extremely accurate images of sensory informationPattern recognitionThe identification of a stimulus on the basis of information already contained in long-term memory

Information that is not quickly passed to short-term memory is gone forever.

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Short-term memory

A limited capacity memory system involved in the retention of information for brief periods

Also used to hold information retrieved from long-term memory for temporary use

Working memoryA memory system which includes STM and mental processes that control retrieval of information from LT memory and interpret that information appropriately for a given task

ChunkMeaningful unit of information which may be composed of smaller units

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The value of chunking

You have 5 seconds to memorize as much as you can.

Then draw an empty chess boards and reproduce the arrangement of the pieces.

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Long-term memory

The memory system involved in the long-term storage of information

One way information is organized is in semantic categories (e.g., animals).

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Conceptual grid10

Types of long-term memories

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Your turn

What kind of memory is your memory for the fact that the earth is round?1. Procedural memory2. Semantic memory3. Episodic memory4. Flashbulb memory

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Your turn

What kind of memory is your memory for the fact that the earth is round?1. Procedural memory2. Semantic memory3. Episodic memory4. Flashbulb memory

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Contents of long-term memoryProcedural memoriesMemories for performance of actions or skills

“Knowing how”

Declarative memoriesMemories of facts, rules, concepts, and events; includes semantic and episodic memory

“Knowing that”

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Contents of long-term memorySemantic memoriesGeneral knowledge, including facts, rules, concepts, and propositions

Episodic memoriesPersonally experienced events and the contexts in which they occurred

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Serial-position effect

The tendency for recall of first and last items on a list to surpass recall of items in the middle of the list

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Your turn

You are asked to recall the following list of letters:Z, S, E, R, F, V, B, H, U, I, K, M, N, G, B, F, OWhich letters are you most likely to remember in long-term memory?1. Z, S, E, R2. F, V, B, H3. U, I, K, M4. G, B, F, O

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Your turn

You are asked to recall the following list of letters:Z, S, E, R, F, V, B, H, U, I, K, M, N, G, B, F, OWhich letters are you most likely to remember in long-term memory?1. Z, S, E, R2. F, V, B, H3. U, I, K, M4. G, B, F, O

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The biology of memory

Forming a memory involves chemical and structural changes at the level of neurons.In short-term memory, changes within neurons temporarily alter the neurons’ ability to release neurotransmitters.In long-term memory, long-term potentiation, a long-lasting increase in the strength of synaptic responsiveness, occurs.

Most researchers believe this is the process underlying learning and memory, yet exact biochemical changes still debated.

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Brain areas involved in memory

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Consolidation10

The process by which a long-term memory becomes durable and stable

Locating memoriesNew brain imaging and testing shows that:During short-term memory tasks, areas of the frontal lobes show activity.

During long-term memory tasks, the hippocampus shows activity.

During encoding of pictures and words, the prefrontal cortex and areas adjacent to the hippocampus show activity.

Procedural memories involve specific changes to the cerebellum.

The formation of long-term memories involves the cerebral cortex.

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Hormones and memoryHormones released by the adrenal glands enhance memory.

One of these, epinephrine, may modulate the level of glucose in the bloodstream.

Memory formation may also be affected by the amount of glucose available in the brain.

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Rehearsal

Maintenance rehearsal: rote repetition of material in order to maintain its availability in memory

Elaborative rehearsal: association of new information with already stored knowledge and analysis of the new information to make it memorable

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Deep processing

In the encoding of information, the processing of meaning rather than simply the physical or sensory features of a stimulus

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Mnemonics

Strategies and tricks for improving memory, such as use of a verse or a formulaMDAS

ROYGBIV

Thirty days hath September. . .

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Decay theory

The theory that information in memory eventually disappears if it is not accessed

Applies more to short-term than long-term memory

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Forgetting curve

Herman Ebbinghaus tested his own memory for nonsense syllables.

Forgetting was rapid at first and then tapered off.

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Linton’s forgetting curve

In contrast to Ebbinghaus, Linton’s memory for personal events was retained over a period of several years and then decreased rapidly.

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Replacement

The theory that new information entering memory can wipe out old informationIn one study, researchers showed subjects slides of a traffic accident.The experimental group was misled into thinking there was a stop sign instead of a yield sign.

Even after being debriefed on the purpose of the study, subjects insisted that they really saw the stop sign.

The new information which came from the researchers replaced what the subjects saw.

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Interference

Similar items interfere with one another.Retroactive interference: forgetting that occurs when recently learned material interferes with the ability to remember similar material stored previously

Proactive interference: forgetting that occurs when previously stored material interferes with the ability to remember similar, more recently learned material

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Cue-dependent forgettingThe inability to retrieve information stored in memory because of insufficient cues for recall

Physical state can be a memory cueState-dependent memory: the tendency to remember something when the rememberer is in the same physical or mental state as during the original learning

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Mood-congruent memory

The tendency to remember experiences that are consistent with one’s current mood and overlook or forget experiences that are not.

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Amnesia

The partial or complete loss of memory of important personal informationPsychogenic amnesia: the causes of forgetting are psychological, such as the need to escape feelings of embarrassment, guilt, shame, disappointment

Traumatic amnesia: the forgetting of specific traumatic events, sometimes for many years

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The repression controversyRepression: in psychoanalytic theory, the selective, involuntary pushing or threatening of upsetting information into the unconscious

Individuals are more likely to struggle with forgetting traumatic events.

It is hard to distinguish repression from other forms of forgetting.

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When should we question recovered memories?If a person claims memories of first year or two of life

If over time the memories become more and more implausible

If therapist used suggestive techniques such as hypnosis, dream analysis, age regression, guided imagery, or leading questions

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Childhood amnesia

The inability to remember events and experiences that occurred during the first two or three years of life

Cognitive explanations:Lack of sense of selfImpoverished encodingA focus on the routineDifferent ways of thinking about the world

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