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

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

Plausible Retrieval  Reder – much of recall is plausible inference not actual recall. 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.  After a delay, plausible inference is faster and does not decay as much as exact memory, with no fan effect.

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

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

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

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

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

Mood Congruence  Bower et al. – hypnotized subjects and induced positive or negative mood. 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.  Mood congruence – easier to remember memories congruent with the current mood.

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

Encoding Specificity  The other items presented during learning provide a context too. Presentation of cues in as close to the original learning context aids recall.  Encoding specificity principle: 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  Watkins & Tulving: Study pairs of words Generate associates for words & indicate which were among studied words. Cued with first word of pair. 61% recall in cued task, <54% in associate recognition task.  Recognition generally produces higher scores so result should have been the opposite of what occurred.

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

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

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

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

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