Cognitive Processes PSY 334 Chapter 7 Human Memory

Cognitive Processes PSY 334 Chapter 7 – Human Memory: Retention and Retrieval August 7, 2003

Inference-Based Intrusions o Sulin & Dooling – subjects add details not present during learning: n n n Carol Harris vs Helen Keller “She was deaf, dumb and blind. ” 5% Carol Harris but 50% Helen Keller subjects falsely recognized the sentence. o Inferences are made at test-time. n More inferential errors occur with delay.

Plausible Retrieval o Reder – much of recall is plausible inference not actual recall. n n Darth Vader inferred to be evil, not remembered to be evil. Heir to hamburger chain story – subjects asked to recall exact details and make plausible inferences. o After a delay, plausible inference is faster and does not decay as much as exact memory, with no fan effect.

Inference and Elaboration o Elaboration leads to more inferences. n Information added as a “theme” to a story results in better recall of studied material and more inferences. o Intruded inferences are not necessarily “errors” but help guide our thinking and behavior. o Listerine court case – false inferences, not just false statements, not permitted.

Memory Errors o When exact memory is needed, inferences and reconstructive processes can be misleading. o Loftus -- additional details and suggestion can change what is recalled. o John Dean’s recall vs what Nixon recorded – gist was right but not details. o False memory syndrome – memories that never happened can be “planted. ”

Structure and Retrieval o Memory is helped by prompts that are closely associated with what is to be recalled. n We prompt ourselves when trying to recall. o Organized material is easier to learn because it provides a structure for prompting recall: n Trees for minerals, animals, clothing, transportation.

Mnemonics o Method of Loci – place items in a location, then take a mental walk. o Peg-word System – use peg words as a structure and associate a list of items with them using visualization. n Create acronyms for lists of items. o Convert nonsense syllables (DAX, GIB) into meaningful items by associating them with real words (e. g. , DAD).

Context Effects o Recall is better if the physical context during learning is also present during testing. n n Experimenter clothing, setting. Under water. o Eich suggests that context effects depend on integrating context and the material to be learned.

Mood Congruence o Bower et al. – hypnotized subjects and induced positive or negative mood. n n Recall better if hypnotized into the same mood during testing as during learning. Again, the effect may depend upon integration of mood with material learned. o Mood congruence – easier to remember memories congruent with the current mood.

State-Dependence o Material is easier to recall if people return to the same emotional and physical state as during learning. n n n Drinking – some state dependence together with overall debilitating effect on memory. Marijuana and tobacco. Caffeine. o Studying when not intoxicated is better.

Encoding Specificity o The other items presented during learning provide a context too. n Presentation of cues in as close to the original learning context aids recall. o Encoding specificity principle: n The probability of recalling an item depends on the similarity of its encoding at test to its original encoding at study.

Test of Encoding Specificity o Watkins & Tulving: n Study pairs of words n Generate associates for words & indicate which were among studied words. n Cued with first word of pair. n 61% recall in cued task, <54% in associate recognition task. o Recognition generally produces higher scores so result should have been the opposite of what occurred.

Amnesia o Studies of amnesics tell us how memory is organized in the brain. o Amnesia occurs with damage to the hippocampus (and some other areas). o Kinds of amnesia: n n Korsakoff’s syndrome Retrograde vs anterograde amnesia o Patient H. M.

What is Spared in Amnesia? o Memory for facts, knowledge of meanings of words, language. o Memory for how to do things (e. g. , play the piano, tie shoes), skills. o Priming o Incidental learning – memory for experience that was not consciously attended to. o Working memory – short term memory.

What is Affected by Amnesia? o Episodic memory – memory for the details and experiences of one’s own life. o Learning and recall of new material -anterograde amnesia n Because conscious learning starts out as an episodic experience.

Implicit vs. Explicit Memory o Explicit memory – knowledge we can consciously recall. o Implicit memory – knowledge we cannot recall but which aids performance on a task. o Amnesics can do a word-completion task but not recall learned words. o Normal subjects also show an explicitimplicit dissociation.

Procedural Memory o Procedural memory can be for skills, but also for doing cognitive tasks. o Berry & Broadbent – control output of hypothetical sugar factory by changing size of workforce (computer simulation): n n Non-obvious formula involved. After 60 trials subjects were good at task but could not state the rule involved. o Amnesics can learn to do this too.