FORGETTING & MEMORY CONSTRUCTION

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 The senses momentarily register amazing detail

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 Encoding Short-term memory Long-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 (Dumb & Dumber example)Dumb & Dumber example Can’t retrieve info that you absolutely know is stored in your LTM

Types of Retrieval Retrieval Cue – a clue, prompt, or hint that can trigger the recall of a stored memory Recall—test of LTM that involves retrieving memories without cues, also termed free recall –Cued recall—test of LTM that involves remembering an item of information in response to a retrieval cue Recognition—test of LTM that involves identifying correct information from a series of possible choices. Serial position effect—tendency to remember items at the beginning and end of a list better than items in the middle.

Recall vs. Recognition tests Importance of retrieval cues evident in recall vs. recognition tests Recall tests - must retrieve info learned earlier. Two step process: 1) generate a mental list, 2) recognize the answer from the 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. –Example: Multiple choice tests

What is the capital of Vermont? Raise your hand if you know the answer

What is the capital of Vermont? A. Brattleboro B. Montpelier C. Rutland D. Cabot Raise your hand if you know the answer Which was easier: recall or recognition? For your psychology exam, would you rather have a fill-in-the-blank or a multiple choice test?

What is the capital of Vermont? A. Brattleboro B. Montpelier C. Rutland D. Cabot Raise your hand if you know the answer Which was easier: recall or recognition? For your psychology exam, would you rather have a fill-in-the-blank or a multiple choice test?

Retrieval cue theories Retrieval cue - a clue, prompt or hint that can help memory retrieval Forgetting the result of using improper retrieval cues Retrieval cue failure – can’t recall LT memories because of inadequate or missing cues. Memories only appear to be forgotten. You are only lacking the right retrieval cue.

Which retrieval cues work best? Encoding Specificity – When conditions of retrieval are similar to conditions of encoding, retrieval is more likely to be successful – You are more likely to remember things if the conditions under which you recall them are similar to the conditions under which you originally learned them

Encoding Specificity Context effects—environmental cues to recall State dependent retrieval—physical, internal factors Mood Congruence—factors related to mood or emotions

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 info than if moved to a new classroom –If learning room smells of chocolate or mothballs, people will recall more info if tested in room with the same smell compared to different smell or no smell at all

Context dependent effects Time of day is also important Learn at 3pmPerform better at 3pm Than 9pm

Context-dependent effects Words heard underwater are best recalled underwater Words heard on land are best recalled on land Water/ land Land/ water Water/ water Land/ land Different contexts for hearing and recall Same contexts for hearing and recall Percentage of words recalled

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 you will be more likely to remember things you learned or did when in that state again.

State dependent effects Drunk doing something Recall better if drunk Than if sober

Mood Congruence Mood Congruence – Mood tends to evoke memories of when you were in that same mood. Positive mood will likely cause you to remember other times you were positive.

Mood Congruence effects –Mood or emotions also a factor –Bipolar depressives Info learned in manic state, recall more if testing done during manic state Info learned in depressed state, recall more if testing done during depressed state

Flashbulb Memory A type of Episodic Memory Memory of an event so surprising or significant to us that it is as if we photographed it in our mind. Why do these happen? –We pay more attention to special events –We think about them more often (repetition) –We connect them to other events in our lives Accuracy declines over time even though it feels extremely accurate

Where were you on September 11, 2001?

Memory and the Brain Play “Remembering What Matters” (8:30) Segment #16 from Scientific American Frontiers: Video Collection for Introductory Psychology (2 nd edition). How does adrenaline affect our ability to remember something? Which part of the brain seems to be active when you form flashbulb memories? How do evolutionary psychologists explain flashbulb memories?

Memory Construction

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 gaps for you like it does for our blind spot

Reconstructing Memories: Sources of Potential Errors – Why the details change over time Two general areas that errors occur in memory reconstruction 1.Info stored before the memory occurred may interfere 2.Info stored after the memory occurred may interfere

Schemas Schemas – organized clusters of knowledge and info about particular topics. What’s your schema for a dog? Contribute to memory distortions when the info learned is inconsistent with previously learned schemas.

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.

Sources of Potential Errors False Memory – distorted and inaccurate memory that feels completely real and is often accompanied by all the emotional impact of a real memory. Source Confusion/Amnesia – true source of the memory (how, when, & where it was acquired) is forgotten. (See box 6.2 on pg. 257 for examples) –Something you’ve heard or seen in a film or book is confused with something that really happened to you Cryptomnesia – a seemingly new or original memory is actually based on an unrecalled previous memory. –Ex. You think you’re remembering a past life but it is actually based on a book you read a long time ago and forgot about. pg. 257

Elizabeth Loftus (1944- ) Does research in memory construction Has found that subjects’ memories vary based on the wording of questions Demonstrated the misinformation effect

Misinformation Effect Incorporating misleading information into one’s memory of an event Affects eyewitness testimony Elizabeth Loftis explains her experiments on Misinformation/attribution effect. (3 min) Misinformation/attribution 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 distort their memories to incorporate the new misleading information Do politicians do this? How?

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? Watch this study explained 1:20-5:35 (4 min)Watch this study explained Accident Leading question: “About how fast were the cars going when they smashed into each other?” Memory construction

Loftus Results Word Used in Question Average Speed Estimate smashed collided bumped hit contacted 41 m.p.h. 39 m.p.h. 38 m.p.h. 34 m.p.h. 32 m.p.h.

Eyewitness Testimony Recall not an exact replica of original events What you recall is a construction built and rebuilt from various sources Often fit memories into existing beliefs or schemas Schema—mental representation of an object, scene or event –Example: schema of a countryside may include green grass, hills, farms, a barn, cows, etc.

Factors that Influence Memory

Memory Construction: Children’s Recall

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 improve “Doctor’s Visit” study – children misremembered 50% of the time when later questioned. See examples from Frontline DocumentaryFrontline Documentary

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 suggest answers

Forgetting as Storage Failure

Motivated Forgetting Undesired memory is held back from awareness –Suppression—conscious forgetting –Repression—unconscious forgetting (Freudian)

Repression Part of Freud’s psychoanalysis 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

Hermann Ebbinghaus ( ) German philosopher who did early memory studies with nonsense syllables Developed the forgetting curve, also called the “retention curve” or “Ebbinghaus curve”

The Forgetting Curve Hermann Ebbinghaus first began to study forgetting using nonsense syllables Nonsense syllables are three letter combinations that look like words but are meaningless (ROH, KUF)

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. Said simply, the more time we spend learning new information, the more we retain.

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 available even under stress

Forgetting Theories Encoding failure Interference theories Motivated forgetting Decay

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 –A decrease in the brain’s ability to encode

Forgetting as encoding failure Info never encoded into LTM Encoding X Long-term memory Encoding failure leads to forgetting Short-term memory

Which is the real penny?

Answer

Encoding Failures Even though you’ve seen thousands of pennies, you’ve probably never looked at one closely to encode specific features

Forgetting as Retrieval Failure: Interference

Interference Theories “Memories interfering with memories” This is ALWAYS BAD for recall Forgetting NOT caused by mere passage of time Caused by one memory competing with or replacing another memory Two types of interference

Two Types of Interference Types of Interference Retroactive Interference Proactive Interference

Retroactive Interference When a NEW memory interferes with remembering OLD information Example: When new phone number interferes with ability to remember old phone number

French 101 Mid-term exam Retroactive Interference Example: Learning a new language interferes with ability to remember old language F- Study French papier livreplume école Study Spanish papel libropluma escuela retroactive interference

Proactive Interference Opposite of retroactive interference When an OLD memory interferes with remembering NEW information Example: Memories of where you parked your car on campus the past week interferes with ability find car today

Proactive Interference Example: Previously learned language interferes with ability to remember newly learned language F-

Review of Interference Theory Retroactive Interference –First Learn A, Then Learn B Recall A, B interferes Proactive Interference –First Learn A, Then Learn B Recall B, A interferes Retro & Pro refer to what you want to remember. Interference reflects competition between responses. How does interference affect us as we age? NBC Report (2 min)NBC Report (2 min)

Decay Theories Memories fade away or decay gradually if unused Time plays critical role Ability to retrieve info declines with time after original encoding Average percentage of information retained 20 mins 1 hr 8 hrs 24 hrs 2 days 6 days 31 days Interval between original learning of nonsense syllables and memory test 100%

Decay Theory Biology-based theory When new memory formed, it creates a memory trace –a change in brain structure or chemistry If unused, normal brain metabolic processes erode memory trace Theory not widely favored today Ability of people to retrieve memories from long ago with retrieval cues would show this is not true.