PPT - UCI Cognitive Science Experiments

Memory Part III Encoding & Retrieval Exceptional Memory

Overview • Causes of Forgetting • Interactions between encoding and retrieval • Exceptional memory performance

Stage theory of memory

Rehearsal

Sensory Memory

Decay

Attention Short-term Memory

Response

Encoding Retrieval

Long-Term Memory

Causes of forgetting in LTM • Inadequate encoding – information is not attended to or is not transferred to LTM • Decay – memory traces decay in strength over time • Interference – memories learned before or after some given memory interfere with retrieval • Distortion – memories are modified over time

Retention Functions • The longer the retention interval (time between learning and retrieval) the greater the chance of forgetting

Ebbinghaus (1885-1913)

Retention & Autobiographical Memory Typically, everyday memory follows Ebbinghaus’ retention function Exception: enhanced memory for events during adolescence & young adulthood  “reminiscence bump”

Schrauf & Rubin (1998)

Causes of forgetting • Inadequate encoding – information is not attended to or is not transferred to LTM • Decay – memory traces decay in strength over time • Interference – memories learned before or after some given memory interfere with retrieval • Distortion– memories are modified over time

Interference • “Memories interfering with memories” – Book calls this effect of “new learning” • Caused by one memory competing with another memory

8

Interference from intervening events • Experiment: ask for recall of previous teams played

Retrieval failures • Forgetting can occur when the wrong retrieval cues are used • Context reinstatement • Cues are useful if they re-create the context in which the original learning occurred • allows the person to use retrieval paths.

Context Reinstatement Memory experiment with deep-sea divers – Deep-sea divers learned words either on land or underwater – They then performed a recall test on land or underwater

Godden & Baddeley (1975, 1980)

State-dependent memory • Memory is enhanced if people learn and recall information in the same physical state

Emotional State-Dependent Memory

90

1. Learn 16 words when happy

2. Placed in happy or sad mood. 3. Asked to recall words

80

Percent Recalled

Learn 16 words when sad

Learn Happy Learn Sad

70 60 50 40 30 Recall Happy

Recall Sad

Kenealy (1997)

State-dependent recall • Study while smoking normal or marijuana cigarette. Test words under same or different physical condition

(Eich et al. 1975)

The Spacing Effect • Spacing effect: Memory is better for repeated information if repetitions occur spaced over time than if they occur massed, one after another

Spacing Effects 1 . 0 M a s s e d R e p e t i t i o n s 0 . 9 0 . 8 0 . 7 0 . 6

S p a c e d R e p e t i t i o n s

Proptincoret

0 . 5 0 . 4 0 . 3 0 . 2

I m m e d i a t e

D e l a y e d

Spaced repetitions better for long term retention. Massed better for short term retention.

Explaining Spacing Effects • Studying material on different occasions (spacing) leads to different encodings of the same material • Because spacing increases encoding variability, there are more ways in which information can be accessed and retrieved at test

Exceptional Feats of Memorization • Cases where people do not forget anything

Patient S • Described in Luria (1975): “The mind of a mnemonist” • “virtually limitless’ memory” • Had capability of synesthesia

• But could also not forget irrelevant details: bad at inductive reasoning (‘filling in the blanks’)

Daniel Tammet • Described in book “Born on a blue day”

• Aspergers syndrome • Has capability of synesthesia

Video (~7 min.)

YouTube: http://youtu.be/Xd1gywPOibg

Superior Autobiographical Memory • Recently, James McGaugh at UC Irvine discovered individuals with highly superior autobiographical memory (HSAM) • Individuals are “normal” – are not autistic or savants – not synesthetes

James McGaugh

Video

Video available at: http://www.cbsnews.com/video/watch/?id=7166313n&tag=topnews Also watch part 2: http://www.cbsnews.com/video/watch/?id=7166315n&tag=contentBody;housing Report from Jan 12, 2014: http://www.cbsnews.com/news/memory-wizards/

Lab testing of Subjects with Highly Superior Autobiographical Memory (HSAM) • Significantly better performance at recalling public as well as personal autobiographical events • However, their performance was comparable to age- and sexmatched controls on most standard laboratory memory tests (e.g. digit span)

• They are not immune to memory distortions (e.g. false memory) • OCD tendencies • Found some enlarged brain areas: the temporal lobe and the caudate nucleus were found to be enlarged

Study of "Memory Athletes" • People who compete in mind games, particularly World Memory Championships and national memory championships • World Memory Championships involve ten events, many of which are like ones psychologists routinely study such as serial recall

[following slides courtesy of Roddy Roediger]

World Records Forward digit span (0-9) – 364 digits – Johannes Mallow Binary Digits 5 min – 1080 digits Johannes Mallow Binary Digits – 30 min – 4,140 digits – Ben Pridmore Speed cards – 21.19 sec – Simon Reinhard

Long Playing Cards (1 hr) – 1,456 cards (28 decks) – Ben P. Long numbers (1 hr) – 2660 digits – Wang Feng

Random words (15 min) – 300 words – Simon Reinhard

Memory Athletes Tested at Un. of Washington St Louis: Ben Pridmore

Nelson Dellis

United Kingdom

USA

Boris-Nikolai Konrad

Germany

Brad Zupp

USA

James Paterson

Simon Reinhard

Johannes Mallow

United Kingdom

Germany

Germany

A Variant of the DRM False Memory Paradigm A powerful false memory paradigm: Semantic + lexical list words related to a “missing” item

bed sweep yawn rest steep pillow sleet awake slope snooze pillow cheap snore sloop slumber sleek… sleep is not presented, but the list words are related to it either semantically or lexically. So activation spreads throughout both lexical and semantic networks. 112 words are presented at a 2 second rate 8 mini-lists of 14 words (7 semantic, 7 lexical)

Memory Athletes Show Superior Discrimination Abilities

Attentional Control • Stroop Task – Name the color of ink of each word that will be presented on screen as quickly and accurately as possible

BLUE DEEP YELLOW BROWN CHAIR . . .

Enhanced Attentional Control for all Superior Memory Individuals

Mean Reaction Time (milliseconds)

800

Congruent

Incongruent

750

700

650

600

550

500 Control

QuizBowl

Memory Athletes

Summary of Findings • Memory athletes have shown exceptional performance on memory tasks, even ones they have never seen • All superior memory groups show better attentional control as reflected by Stroop interference than a college control group