Cognitive Processes PSY 334 Chapter 7 – Human Memory: Retention and Retrieval May 14, 2003

Interference vs Decay  Less forgetting during sleep than when awake. Occurs because material is retained better when learned at night. Night is period of highest arousal.  Forgetting functions may reflect interference from unknown sources.  Decay theories do not specify any mechanism for decay.

Effects of Redundancy  Interference occurs only when learning multiple memories that have no relationship to each other.  Bradshaw & Anderson – compared relevant and irrelevant fact learning: Irrelevant facts interfere. Relevant facts aid memory compared to single fact learning.

Retrieval and Inference  Much of memory is inference at the time of recall – not actual recall of facts.  Bransford et al. -- inference can lead to incorrect recall: Turtles resting on or beneath log. Subjects were most confused by sentences whose meaning was implied by the studied sentences.

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).