Forgetting

DO NOW How would damage to the hippocampus affect an individual’s memory? – Think about Patient H.M.

Two Types of Amnesia

Memory and the Hippocampus Hippocampus turns STM into LTM

Biological Forgetting Factors Damage to the Hippocampus – Difficulty forming new memories – Diminished in Alzheimer’s patients – Head injuries/concussions Neurotransmitters play a role – Acetylcholine - Alzheimer’s patients show low levels of this – Alcohol and other drugs (black outs) Stress Hormones – enhance memories – stress is a reaction to danger, our brain wants us to remember dangerous things to protect us in the future

Forgetting as Encoding Failure

Encoding Failures People fail to encode information because: – It is unimportant to them – It is not necessary to know the information

Which is the Right Penny? (From Nickerson & Adams, 1979)

Forgetting as Storage Failure

DECAY THEORY: Memories deteriorate due to the passage of time EBBINGHAUS CURVE aka. FORGETTING CURVE

Forgetting as Retrieval Failure

Interference A retrieval problem when one memory gets in the way of remembering another Two types of interference: – Proactive interference – Retroactive interference

Proactive Interference When an older memory disrupts the recall of a newer memory. – Remembering last year’s locker combination, not this years – Calling a significant other by your ex’s name

Retroactive Interference When a more recent memory disrupts the recall of an older memory. – Can remember your current class schedule but not schedules from past years – Can remember how to do tasks on your current phone but not an older one

Figure 7.19 Retroactive and proactive interference

Motivated Forgetting - REPRESSION Sigmund Freud’s psychoanalytic theory Process of moving anxiety-producing memories to the unconscious Supposed means of protecting oneself from painful memories Not well-supported by research; stressful incidents are actually more likely to be encoded

Figure 7.20 Estimates of the prevalence of childhood physical and sexual abuse

19 Tip-of-the-Tongue (ToT) State: – A feeling that one knows a response yet is unable to produce it Brown and McNeil (1966) – Is the feeling of knowing an illusion? – Task: Retrieve the word corresponding to its provided definition – e.g. “A musical instrument comprising a frame holding a series of tubes struck by hammers” Participants were asked to indicate if they were in a ToT state – If so, guess the number of syllables and any other information about the word (e.g. first letter) – Results: Participants are better at remembering associated information than they were at producing the actual word (e.g. XYLOPHONE) Tip-of-the-Tongue Phenomenon