FORGETTING INTRO

FORGETTING

&

Why do we forget?

• _Forgetting

can occur at any

memory stage

Retrieval from long-term memory

Depending on interference, retrieval cues, moods, and motives, some

things get retrieved, some don’t

Long-term storage

Some items are altered or lost

Short-term memory

A few items are both noticed and encoded

Sensory memory

Hermann Ebbinghaus

(1850-1909)

• _{German philosopher who did early}

memory studies with nonsense syllables

• _{Developed the forgetting curve, also}

The Forgetting Curve

Hermann Ebbinghaus first began to study forgetting using nonsense syllables

Nonsense syllables are three letter

Ebbinghaus’ Forgetting Curve

• Ebbinghaus found

that the more

times he practiced a list of nonsense syllables on day 1, the fewer

repetitions he

required to relearn it on day 2.

• Put simply, the

more time we spend learning new information, the more we

How to combat the Forgetting Curve:

Overlearning

• _{Continuing to rehearse after the point}

the information has been learned

• _{Rehearsing past the point of mastery} • _{Helps ensure information will be}

Forgetting as retrieval failure

• _{Retrieval—process of accessing stored information} • _{Sometimes info IS encoded into LTM, but we can’t}

retrieve it

Retrieval failure leads to forgetting

Retrieval

X

Short-term memory

Tip of the tongue phenomenon

• _{TOT—involves the sensation of knowing}

that specific information is stored in

long-term memory but being unable to retrieve it

• _{Can’t retrieve info that you absolutely}

Recall vs. Recognition tests

• _{Recall tests - must retrieve info learned earlier.} • _{Two step process: 1) generate a mental list, 2)}

recognize the answer from your list.

– _{Examples: Fill-in-the-blank test; essay exams}

• _{Recognition tests - only need to identify the correct} answer.

• _{1 step process: 1) recognize answer from the list.} List was already generated for you.

What is the capital of Australia?

What is the capital of Australia?

• _{A. Hull}

• _{B. Sydney} • _{C. Canberra} • _{D. Perth}

• _{Raise your hand if you know the answer} • _{Which was easier: recall or recognition?}

Retrieval Cue Theories

• _{Forgetting the result of using improper}

retrieval cues

• _{Retrieval cue failure – inability to recall LT}

memories because of inadequate or missing cues.

• _{Memories only appear to be forgotten. You}

Which retrieval cues

work best?

• _{Context-dependent memory - improved}

ability to remember if tested in the same environment as the original learning

environment

– _{Better recall if tested in classroom where you initially}

learned information

– _{If learning room smells of chocolate or mothballs,}

people will recall more info if tested in room with the same smell

State-dependent effects

• Recall improved if internal physiological or

emotional state is the same during testing and initial encoding

• _{If you are in an altered state of consciousness}

Mood Congruence

• _{Mood Congruence – Mood tends to evoke memories} of when you were in that same mood.

Mood Congruence effects

Example:

Bipolar depressives

• _{Info learned in manic state, recall more if} testing done during manic state

Reconstructing Memories:

Sources of Potential Errors –

Why the details change over time

•

Interference of

new or old

Sources of Potential Errors

• _{Source Confusion – true source of the memory} (how, when, & where it was acquired) is

forgotten.

• _{False Memory – distorted and inaccurate memory} that feels completely real and is often

Memory

Jigsaw

Analogy

• Memories, rather than being like a

video tape, are formed as bits and pieces.

• People may retrieve only some of the

pieces of the memory

• Brain fills in the blanks and doesn’t

Elizabeth Loftus

• _{Has found that subjects’ memories}

vary based on the wording of questions

• _{Demonstrated the}

Misinformation Effect

• _{Incorporating misleading information}

into one’s memory of an event

• _{Affects eyewitness testimony}

• _{Elizabeth Loftus explains}

her experiments on

Misinformation/attributio n effect

Memory Distortion

• _{Memory can be distorted as people try}

to fit new info into existing schemas

• _{Giving misleading information after an}

event causes subjects to unknowingly

Loftus Experiment

• _{Subjects shown video of}

an accident between two cars

• _{Some subjects asked:}

How fast were the cars going when they

smashed into each other?

• _{Others asked: How fast}

were the cars going when they hit each other?

Accident

Leading question:

“About how fast were the cars going when they smashed into each other?”

Eyewitness Testimony

•

Scripts—type of schema

– _{Mental organization of events in time}

– _{Example of a classroom script: Come into} class, sit down, talk to friends, bell rings, instructor begins to speak, take notes, bell rings again, leave class, etc.

Eyewitness Testimony

• Not an exact replica of original events

• _{What you recall is a construction built and} rebuilt from various sources

• _Often

fit

• _{Schema—mental representation of an object,} scene or event

– _{Example: schema of a countryside may include green grass,}

Memory

Construction:

Children’s Testimony on Abuse

• _{Research has shown children’s}

testimony to be unreliable

• _{Children are very open to suggestions} • _{As children mature their memories}

Accurate Interviewing Methods

• _{To promote accuracy with children’s}

testimony the interviewer should:

–_{Phrase questions in a way the child can}

understand

–_{Have no prior contact with the child}

–_{Use neutral language and do not lead or}

Forgetting Theories

• _{Encoding failure} • _Interference

theories

• _Motivated

forgetting

Forgetting as

Encoding Failures

You never remembered it in

the first place!

• People fail to encode information

because:

–It is unimportant to them

–It is not necessary to know the

information

–A decrease in the brain’s ability to

Forgetting as encoding failure

• Info never encoded into LTM

Encoding

X

memory

Encoding failure leads to forgetting

Encoding Failures

Even though you’ve seen thousands of

pennies, you’ve probably never

Forgetting as

Interference Theories

• _{“Memories interfering with memories”} • _{Forgetting NOT caused by mere passage}

of time

• _{Caused by one memory competing with}

Two Types of Interference

Types of Interference

Retroactive Interference

French 101 Mid-term

exam

Retroactive Interference

• When a NEW memory interferes with remembering OLD information

• Example: Learning a new language interferes with ability to remember

Proactive Interference

• _{Opposite of retroactive}

interference

• _{When an OLD memory}

interferes with remembering NEW information

• _{Example: Memories of}

Motivated Forgetting

(I meant to forget it?)

Undesired memory is held back from

awareness

–_{Suppression—conscious forgetting} –_{Repression—unconscious forgetting}

Repression

• Part of Freud’s psychoanalysis

• Process of moving anxiety-producing memories to the unconscious

• _{Supposed means of protecting oneself} from painful memories

Decay Theories

• _{Memories fade away}

or decay gradually if unused

• _{Time plays critical}

role

• _{Ability to retrieve}

info declines with time after original encoding

• _{If unused, normal}

brain metabolic processes erode memory trace Average percentage of information retained 0 10 20 30 40 50 60 70 80 90 100 20

mins hr1 hrs8 hrs24 days2 days6 days31

Interval between original learning of nonsense syllables and memory test

Amnesia

• _{Infantile – don’t accurately remember much of your}

childhood (2 & under) due to your hippocampus not being fully developed.

• _{Anterograde – injury that prevents new memories from}

forming

• _{Retrograde – injury that prevents memory from before the}