Transcript 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
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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
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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
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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