Transcript No Slide Title

EXP6939
HUMAN MEMORY
• Focus and structure of course
• A brief personal history
• Some themes in the study of
memory
• Prescientific perspectives on
memory
• A Science of memory: methods and
measures
• Assignments for next week
THEMES IN THE STUDY OF
HUMAN MEMORY
(Baddeley, Ch. 1)
• How should memory be described?
– Phenomenological
– Information processing
– Biological
• What does it include? Is memory
singular or plural?
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Episodic versus semantic
Declarative versus procedural
Short term versus long-term
Implicit versus explicit
• How are lab studies related to
“everyday memory?”
– The issue ecological validity
– Areas of “applied memory research”
SCHACTER’S THEMES:
MEMORY’S “FRAGILE POWER”
• Memory is powerful
– Who we are is what we remember
– Its role in everyday tasks
– Normally functions in the background
• Memory is fragile
– Omissions, distortions and constructions
in everyday life
– These may be adaptive
– It’s vulnerable to a host of impairments
• Memory is not singular
– Differences based on duration, content,
accessibility
– Different processes can be selectively
impaired
– And tied to different brain regions
– The search for “dissociations”
MEMORY’S FRAGILE POWER
(cont’d)
• Remembering is an act of synthesis
– Combining fragments of the past with
present state and goals
– Memory as an attribution
– Different subjective states of memory
(e.g., remember or know?)
• Memory has both automatic and
effortful aspects
– Most remembering as a mixture of the
two
– Different brain regions involved in
automatic and strategic aspects of
memory?
MEMORY THROUGH THE AGES
Prescientific perspectives
Ancient gods for memory
Greek and Roman philosophy
• Plato (427-347 BC)
– Innate concepts and memories
– Metaphoric mechanisms for
• Encoding (a scribe; misencoding)
• Storage (wax tablet; distortable)
• Retrieval (aviary; retrieval failure)
• Aristotle (384-322 BC)
– Retention & knowing versus
“recollection”
– Nature of representation
– Individal differences in memory
– Laws of association in recall
• Contiguity, similarity, contrast
– Automatic and effortful retrieval
– Potential for false memory and
source amnesia
Aristotle’s On Memory and
Reminiscence (c. 350 bc)
• Memory vs. recollection
– Memory is necessary, not sufficient for
recollection
– Recollection a form of inference
(attribution?) placing ourselves in a
certain time and space
– Some phrases sound like implicit/explicit,
some availability/accessibility
• Recollection and association
– Retrieval as “movement” between related
memories
– Associative “laws” (contiguity, similarity)
– Automatic cuing vs. effortful search
• Interesting comments about:
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Rehearsal and practice
Concrete vs. abstract “codes”
Role of the “substrate” (hard/soft walls)
Recollection may be in error
Arousal hurts memory
Dwarfs have lousy memory
“Aristotle was the sort of universal Genius who
makes three-paragraph summaries about him seem
peculiarly lightheaded and perverse.” [Murphy &
Kovach, Historical Introduction to Modern
Psychology]
• Cicero (106-43 BC)
– Practical aspects of memory
– “method of loci” for remembering order
• Augustine (354-430 AD)
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Sensory vs. ‘intellectual” memories
Active nature of remembering
Potential for “false memories”
Importance of emotion in memory
The Renaissance:
Empirical observation
• Juan Luis Vives (1492-1540)
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Spanish humanist/empiricist
“Three Books on the Soul of Life” (1538)
Importance of rehearsal for retention
Utility of “memory exercise” and practice
Three sources of forgetting
• “image’ is erased or destroyed
• Smeared or fragmented
• Or “escapes our search”
• Francis Bacon (1561-1626)
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British philosopher/humanist
Describes the “inductive method”
Basic skills of memory, fancy, reason
Mnemonic strategies
• Visual imagery
• Study prior to sleeping
• Varied encoding
• Selective memory search
(“prenotion”)
British Empiricism and
Continental Nativism
• Thomas Hobbes (1588-1679)
– Memory as “decaying sensations”
– Knowledge results from experience
– Founds British empiricist tradition
(Locke, Hume, Hartley, Mill)
• Rene Descartes (1596-1650)
– Mental laws vs. physical (dualism)
– Importance of innate concepts and
processes
A SCIENCE OF MEMORY
• Herman Ebbinghaus (1850-1909)
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Prussian philosopher
Steeped in British empricist approach
“Uber das Gedachtnis” (1885)
First experimental work on memory
Introduces basic controlled methods
Describes basic memory phenomena
• Learning and forgetting functions
• List-length effects and STM span
• Serial position and spacing effects
• Remote and backward associations
• Importance of meaningfulness and
organization
– Contrasts effortful and automatic
retrieval
– Contrasts explicit and implicit
memory
DESIGNING A MEMORY
EXPERIMENT
• Manipulation versus control
• Whose memory will we study?
– Effects of age, gender, disorders,
expertise
• What state are they in?
– Arousal, mood, motivation
• What is the object of memory?
– Verbal or nonverbal material
– Simple or complex structure
– Learned in the lab or elsewhere
• What are the conditions of
presentation?
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Visual, auditory or other modality
Number of presentations
Sequence of presentations
Time between presentations
Context of presentations
• What will they do with the material?
– Intentional or incidental instructions
– Special encoding tasks
• Who gets what conditions?
– Between-group or within-subject
• How long is the retention interval?
– Immediate (STM, seconds to tens of sec)
– Recent (LTM, minutes to hours)
– Remote (LTM, months to decades)
• What is the memory task?
– Explicit tests of memory
• Free or cued recall
• Recognition
– Implicit tests of memory
• Repetition priming, fragment completion
• What attribute(s) do we test?
– Identity, frequency, position, sequencing
of items
MEASURING MEMORY:
THE DEPENDENT VARIABLES
• Performance measures
– Accuracy, speed of response
• Potential for speed-accuracy trade-offs
Attention Condition
Full
Divided
RT(ms) 620
540
errors (%) 4
6
– Types of errors
• omission, commission, distortions in recall
• Hits and false alarms in recognition
Proportion “old” words
High Low
Hits
.80
.40
False Alarms
.30
.05
d’
1.37 1.39
• Subjective judgments
– Confidence
• Is confidence correlated with accuracy?
– Qualitative judgments (remember-know)
• Physiological markers
– Measures of CNS: Blood flow
• Positron emission tomography (PET)
• Magnetic resonance imaging (MRI, fMRI)
– Measures of CNS: electromagnetic activity
• Electroencephalography (EEG, ERP)
• Magentoencephaolography (MEG)
• Optical imaging (EROS)
– Measures of ANS activity
• Galvanic skin responses (GSR)
• Muscular activity (EMG)
• Heart, respiration rate
AN OBSESSION WITH MEMORY
• Marcel Proust’s In Search of Lost
Time
– 1908-1922; 8 volumes, 3,000 pages
– Recollections, and meditations
• “I understood that all the material of a literary
work was in my past life, I understood that I
had acquired it in the midst of frivolous
amusements, in idleness, in tenderness and
in pain, stored up by me without my divining
its destination or even its survival, as the
seed has in reserve all the ingredients which
will nourish the plant.”
TWO CASES OF AMNESIA
• GR (from Schacter 96)
– 67-yr old Italian poet & artist
– Stroke damages left thalamus
– Almost complete amnesia for “episodic
past” (retrograde amnesia)
– Little ability to remember new events
(anterograde amnesia)
– Near-full recovery a year later
• Sheila (from Campbell & Conway 95)
– 32-yr old school teacher
– Severe herpes encephalitis
– Damage to temporal lobes, right frontal
lobes
– Mild RA, profound AA (the classic
“amnestic syndome”
– Little hope for recovery
A RECENT CASE OF “MEMORY
THEFT”
• Binjamin Wilomirski’s “Fragments”
– 1995 book by Holocaust survivor
– 1999: Expose by Ganzfried
– Was it fraud? Or misconstruction?
REMEMBERING VERSUS
KNOWING
• The remember-know distinction
(Tulving, 85)
– Importance of contextual and sensory
detail of episode
• Dissociations based on
– Divided attention at study selectively
reduces “remember” judgments (Gardiner
& Parkin, 1995)
– Elaborative encoding at study selectively
enhances “remember” judgments, and
– Study of pictures versus words selectively
enhances “remember” judgments
(Rajaram, 1993)