chapter 6 memory
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Chapter 6 Memory. Dec 10 th , 2012. Memory. Memory: Active system that receives, stores, organizes, alters, and recovers (retrieves) information Acquired Encoding Stored in the brain Storage Later retrieved Retrieval Eventually (possibly) forgotten. Figure 7.2. - PowerPoint PPT PresentationTRANSCRIPT
Dec 10th, 2012
MemoryMemory: Active system that receives,
stores, organizes, alters, and recovers (retrieves) informationAcquired
EncodingStored in the brain
StorageLater retrieved
RetrievalEventually (possibly) forgotten
Figure 7.2
FIGURE 7.2 Remembering is thought to involve at least three steps. Incoming information is first held for a second or two by sensory memory. Information selected by attention is then transferred to temporary storage in short-term memory. If new information is not rapidly encoded, or rehearsed, it is forgotten. If it is transferred to long-term memory, it becomes relatively permanent, although retrieving it may be a problem. The preceding is a useful model of memory; it may not be literally true of what happens in the brain
Three-Box Model of Memory
Sensory MemoryFunction - holds
information long enough to be processed for basic physical characteristics
Capacity - largecan hold many items at
onceDuration - very brief
retention of images0.3 sec for visual info2 sec for auditory info
Sensory
InputSensory Memory
Sensory Memory
Divided into two subtypes:iconic memory - visual
informationechoic memory -
auditory informationVisual or iconic memory
was discovered by Sperling in 1960
Sensory
InputSensory Memory
Sperling’s ExperimentPresented matrix of letters
for 1/20 secondsWhole-report procedure
Participants are asked to report all the items of a display
Partial-report procedureParticipants are cued to
report only some of the items in a display
Sperling’s Iconic Memory Experiment
Sperling’s Iconic Memory Experiment
Sperling’s Iconic Memory Experiment
Sperling’s Iconic Memory Experiment
Sperling’s ExperimentSounded low, medium
or high tone immediately after matrix disappearedTone signaled 1 row to
reportRecall was almost perfect
Memory for images fades after 1/3 seconds or so, making report of entire display hard to do
High
Medium
Low
Results from Sperling’s experiment demonstrating the existence of a brief visual sensory store. Participants were shown arrays consisting of three rows of four letters. After the display was turned off, they were cued by a tone, either immediately or after a delay, to recall a particular one of the three rows. The results show that the number of items reported decreased as the delay in the cuing tone increased.
Sensory Memory
Sensory memory forms automatically, without attention or interpretation
Attention is needed to transfer information to working memory
Sensory
InputSensory Memory
Short-Term Memory (STM) A proposed intermediate system in
which information has to reside on its journey from sensory memory to long-term memory
Atkinson and Shiffrin (1968) Model
Proposes that as information is rehearsed in a limited-capacity STM, it is deposited in long-term memory
Memory spanThe number of elements one can
immediately repeat backTypical short-term memory span is about
seven items of information (i.e., words)George Miller (1957)Shepard and Teghtsoonian (1961)
Information cannot be kept in STM indefinitely
George Miller
“The magical number seven, plus or minus two: Some limits on our capacity for processing information” (1956)
Working MemoryHolds the Information Needed to Perform a task
Memory system that provides temporary storage for information that is currently being used in some conscious capacity (Baddeley, 1986)Function - conscious processing of information
where information is actively worked onCapacity - limited (holds 7 +/- 2 items) Duration - brief storage (about 30 seconds)Code - often based on sound or speech even
with visual inputs
Reading 1
Baddeley’s theory of working memory in which a central executive coordinates a set of slave systems.
Working MemoryThe Central Executive
An attentional control mechanism for working memory Coordinating between the various subsystems Temporary activation of long-term memory Shifting between tasks or retrieval strategies Relying on the frontal lobe, mainly in the left hemisphere
Use of language clearly relies on the central executive
Working MemoryThe visuospatial sketchpad
Integrating spatial, visual, and kinesthetic informationPhonological loop
Articulatory loop‘Inner voice’ used during rehearsal of verbal informationAble to maintain about 1.5 to 2 sec worth of material in
the loopPhonological store
An ‘inner ear’ that hears the inner voice and stores the information in phonological form
Word length effectwit, sum, harm, bay, topUniversity,opportunity,aluminum,constitutional,au
ditorium
Working Memory
Phonological similarity effect"G, C, B, T, V, P” vs. “F, L, K, S, Y, G.”
Performance is usually _____ when the items sound similar than when the items sound different.
The phonological store retains speech-based memory for a brief period of time and unless material is rehearsed, it usually decays within 2 seconds.
The articulatory control process, which is responsible for translating visual information into speech-based codes, as well as transfering it to the phonological store.
Processing depth
Elaboration leads to better recall than shallow processing
Typ
e of
P
roce
ssin
g
Shallow -Acoustic
Deep
Shallow - Visual
10 20 30 40 50 60 70 80 90 1000Percent of words recalledPercent of words recalled
10 20 30 40 50 60 70 80 90 1000
Working Memory measures Digit span(Wechsler, 1974)
Forward digit span (Botwinick & Storandt, 1974) Backward digit span (Gathercole & Alloway, 2008) Letter-number sequencing (Wechsler, 1997)
Nonword repetition(Obrien et al., 2006) Wisconsin Card Sorting Test (WCST) (Miyake et al., 2000) Tower of Hanoi (TOH)/London (Korkman, Kirk, & Kemp, 1998) Random number generation (RNG) (Baddeley, 1998) Operation span (Miyake et al., 2000) Dual task (Papagno et al., 1991) N-back (Smith & Jonides, 1999) Delayed-recognition (Jha & McCarthy, 2000)
An illustration of the delayed match-to-sample task
Working MemoryThe Frontal Cortex and Primate Working Memory
•Delayed match-to-sample tasks with monkeys (Goldman-Rakic, 1992)• Monkeys with lesions in the frontal cortex
cannot perform this working memory task.• Human infants cannot perform similar
tasks successfully until their frontal cortices have somewhat matured (around 1 year)
Lateral views of the cerebral cortex of a human (top) and of a monkey (bottom). Area 46 is the region shown in darker color.
• Auditory-Verbal maintenance deficit following Left Supramarginal / Inferior Parietal lesions, eg KF (Warrington & Shallice, 1969)
• Visual-spatial maintenance deficit following Right Inferior Parietal lesion, eg ELD (Hanley et al 1991)
• Frontal patients impaired on manipulating information in Working Memory on tasks such as card sorting (Milner, 1963) and selection-without-repetition (Petrides & Milner, 1982)
• Age-related Working Memory deficits following frontal-striatal decline (Gabrieli, 1996)
Modality-specific, passive stores in posterior parietal/temporal cortex Common executive processes in frontal cortex
Working Memory - Neuropsychology
Neural Correlates of Working MemoryThe phonological loop – Speech
Left hemisphere: frontal and parietal regions
The visuo-spatial sketchpad – NonspeechRight hemisphere
The central executive – Domain generalFrontal lobe and ACC (anterior
cingulate cortex)
Anderson, Cognitive Psychology and Its Implications, Edition 7e – Chapter 6
Awh et al., 1996
Anderson, Cognitive Psychology and Its Implications, Edition 7e – Chapter 6
Modality independent(Schumacher et al., 1996)
Anderson, Cognitive Psychology and Its Implications, Edition 7e – Chapter 6
Baddeley, 2003
Memory aidsChunkingHierarchical organizationRehearsal
ChunkingGrouping small bits of information into larger
units of informationexpands working memory load
Which is easier to remember?4 8 3 7 9 2 5 1 6
483 792 516
Related items clustered together to form categoriesRelated categories clustered to form higher-order
categoriesRemember list items better if list presented in categories
poorer recall if presented randomlyEven if list items are random, people still organize info in
some logical pattern
Hierarchical Organization
Figure 7.4
FIGURE 7.4 A hypothetical network of facts about animals shows what is meant by the structure of memory. Small networks of ideas such as this are probably organized into larger and larger units and higher levels of meaning.
Training your working memory
Working MemoryBaddeley’s Theory of Working Memory (2003)
Memory FormationRetrograde Amnesia: Forgetting events that
occurred before an injury or traumaAnterograde Amnesia: Forgetting events that
follow an injury or traumaConsolidation: Forming a long-term memoryElectroconvulsive Shock (ECS): Mild electrical
shock passed through the brain, causing a convulsion; one way to prevent consolidation
AmnesiaRetrograde AmnesiaLoss of past memory
Anterograde AmnesiaCan’t form new memories
Anterograde Amnesia
Figure 7.5
FIGURE 7.5 The tower puzzle. In this puzzle, all the colored disks must be moved to another post, without ever placing a larger disk on a smaller one. Only one disk may be moved at a time, and a disk must always be moved from one post to another (it cannot be held aside). An amnesic patient learned to solve the puzzle in 31 moves, the minimum possible. Even so, each time he began, he protested that he did not remember ever solving the puzzle before and that he did not know how to begin. Evidence like this suggests that skill memory is distinct from fact memory.
Long-Term Memory
Long-Term Memory
Explicit Implicit
Available to conscious retrievalAvailable to conscious retrieval
Can be declared Can be declared (propositional)(propositional)
ExamplesExamples ““What did I eat for What did I eat for
breakfast?”breakfast?” (episodic)(episodic) ““What is the capital of What is the capital of
Spain?”Spain?”(semantic)(semantic) ““What did I just say?”What did I just say?”
(working)(working)
Experience-induced change in Experience-induced change in behaviourbehaviour
Cannot be declared Cannot be declared (procedural)(procedural)
ExamplesExamples Subliminal advertising?Subliminal advertising?
(priming)(priming) How to ride a bicycleHow to ride a bicycle
(skills)(skills) PhobiasPhobias
(conditioning)(conditioning)
Long-term Memory
Declarative Non-declarative
SemanticEpisodic Priming Procedural Conditioning
What did I have for
breakfast?
What is the capital of France?
Facilitated
processing
Reflex response to new stimuli
How to ride a bicycle
Explicit MemoryAlso known as declarative or conscious memory
Properties:memory consciously recalled or declaredCan use to directly respond to a question
Two subtypes of explicit memory
Episodic MemoryMemory tied to your own personal experiences
Examples:what did you have for dinner?do you like to eat caramel apples?
Why are these explicit memories?
Because you can actively declare your answers to these questions
Semantic MemoryMemory not tied to personal eventsGeneral facts and definitions about the worldExamples:
who was George Washington?what is a cloud?what is the climate at the north pole?
These are explicit memories because you can describe what you know about them.
Unlike episodic memories, your knowledge does NOT include your personal experience i.e., You may never have been to the north pole but do know
about it.
Implicit MemoryAlso known as nondeclarative memory
Influences your thoughts or behavior, but does not enter consciousness
Three subtypes
Classical Conditioning
Studied earlier Implicit because it
is automatically retrieved
PrimingPriming is influence of
one memory on another
priming is implicit because it does not depend on awareness and is automatic
Here is a demonstration
Unscramble the following words:
O R E S L T E P AK T A L S TSME L O B S O M SELAF
Procedural MemoryMemory that enables you to perform specific learned
skills or habitual responsesExamples:
Riding a bikeHow to speak grammaticallyTying your shoe laces
Why are these procedural memories implicit?Can’t readily describe their contents
try describing how to tie your shoesThey are automatically retrieved when appropriate
Mirror Tracing Mirror Tracing (e.g. Corkin, 1968)(e.g. Corkin, 1968)
Rotary–PursuitRotary–Pursuit(e.g. Gabrieli et al., 1997)(e.g. Gabrieli et al., 1997)
Serial Reaction TaskSerial Reaction Task(e.g. Hazeltine et al., 1997)(e.g. Hazeltine et al., 1997)
Procedural - Procedural - NeuropsychologyNeuropsychology
Amnesic patients show intact: Rotary Pursuit (Corkin 1968) Serial Reaction Task (Nissen & Bullemer 1987)
Alzheimer’s patients show intact: Rotary Pursuit (Gabrieli et al 1993) Mirror Tracing (Heindel et al 1989)
Parkinson’s patients impaired on: Rotary Pursuit (Heindel et al 1989) Serial Reaction Task (Ferraro et al 1993)
Huntington’s patients impaired on: Rotary Pursuit (Gabrieli et al 1997) Serial Reaction Task (Willingham & Koroshetz 1993)
but not: Mirror Tracing (Gabrieli et al 1997)
Cerebellar lesions impair Mirror Tracing (Sanes et al 1990)
Procedural - Procedural - NeuroimagingNeuroimaging
Rotary Pursuit learning correlates with activity in Primary and Secondary Motor Cortex (Grafton et al 1992)
Serial Reaction Task correlates with activity in Primary and Secondary Motor Cortex, and Basal Ganglia (Hazeltine et al 1997)
Two hypotheses:
1. Learning repetitive sequence involves Basal Ganglia-Thalamic-Motor Cortical loop Learning new visual-motor mappings involves Cerebellar-Motor Cortical loop
2. Open-loop learning (minimal feedback): Basal Ganglia-Thalamic-Motor Cortical loop
Closed-loop learning (continual feedback): Cerebellar-Motor Cortical loop
Rotary Pursuit and Serial Reaction Task involve open-loop motor learning with little visual feedback (impaired by Basal Ganglia lesions)
Mirror Tracing involves much visual feedback (impaired by Cerebellar lesions)
Need to examine nonvisual feedback
• MTL activations during episodic encoding (Tulving et al 1996) and retrieval (Schacter et al. 1996)
Anterior-Posterior dissociation? (Lepage et al. 1998; Schacter et al. 1999)
• Left Frontal during Encoding (Shallice et al., 1994), right during Retrieval
“HERA: Hemispheric Encoding Retrieval Asymmetry” (Tulving et al., 1994)
• Posterior cingulate / Precuneus (Fletcher et al., 1996)
• Left lateral inferior parietal cortex (Henson et al., 1999)
Network of Frontal - Medial Temporal – Posterior areas all involved:
Frontal areas control encoding and retrieval of memories?
Posterior association areas store components of memories?
Medial Temporal regions (temporarily) bind different components?
• Finer spatial resolution (fMRI) beginning to dissociate MTL regions, eg Hippocampus / Perirhinal for “Recollection / familiarity”? (Aggleton & Brown, 1999)
Episodic Memory - Neuroimaging
• Common activation in Left Inferior Frontal, Inferior Temporal, Angular gyrus and Temporal pole for semantic judgments to words and pictures (Vandenberghe et al 1996)
• Left Inferior Temporal activations for animal and tool naming, Temporal Pole for people naming (Damasio et al., 1996)
• Left Inferior Temporal activation for category- versus letter-fluency (Mummery et al 1996)
• Left Middle Temporal and Premotor activations for tool vs animal naming, Left Middle Occipital for animal vs tool naming (Martin et al 1996)
Distributed representations, with activations reflecting object’s interaction with world? E.g., tool naming activates motor regions
Semantic Memory - Neuroimaging
McClelland and Rogers, 2003
Basic Neuroanatomy of MemoryA) Subcortical structuresBasal ganglia and cerebellum –
Procedural memory. Caudate nucleus involved particularly with habit formation (unconscious learning)
Thalamus – Temporal sequencing information. Also supplementary role to medial temporal lobes in new learning
Basal forebrain – The binding together of different modal components in episodic memory
B. Cortical structuresHippocampus – Acquisition of new
factual knowledgePrimary association cortex – Visual,
auditory and somatosensory dataNon-medial temporal – Retrieval of
previously learned material e.g. autobiographical info, names, faces
Ventromedial frontal lobes – Memory traces linking facts and emotion
Dorsolateral frontal lobes – Recency and frequency memory. Working memory
Memory
Declarative Non-declarative
SemanticEpisodic Priming Procedural Conditioning
What did I have for
breakfast?
What is the capital of France?
Facilitated
processing
Reflex response to new stimuli
Medial temporal
Diencephalon Mammillary
bodiesFrontal lobe
LateralTemporal /
Frontal lobes
Many cortical
regions… Cerebellum/Amygdala
(MTL?)
How to ride a bicycle
Basal Ganglia
CerebellumMotor cortex
Measuring MemoryTip-of-the Tongue (TOT): Feeling that a memory is
available but not quite retrievableFeeling of Knowing: Feeling that allows people to
predict beforehand if they will be able to remember something (typically seen on game shows like Jeopardy)
Recall: Supply or reproduce facts or information with some external cues; direct retrieval of facts or informationHardest to recall items in the middle of a list;
known as Serial Position Effect Easiest to remember last items in a list because
they are still in STM
Figure 7.7
FIGURE 7.7 The serial position effect. The graph shows the percentage of subjects correctly recalling each item in a 15-item list. Recall is best for the first and last items.
Measuring Memory (cont'd)Recognition Memory: Identifies correctly
previously learned materialUsually superior to recall
Distractors: False items included with a correct itemWrong choices on multiple-choice tests
False Positive: False sense of recognition
Figure 7.8
FIGURE 7.8 (a) “Treasure map” similar to the one used by Kosslyn, Ball, and Reiser (1978) to study images in memory. (b) This graph shows how long it took subjects to move a visualized spot various distances on their mental images of the map.
Eidetic Imagery (Somewhat Like Photographic Memory)Occurs when a person (usually a child) has visual
images clear enough to be scanned or retained for at least 30 seconds
Usually projected onto a “plain” surface, like a blank piece of paper
Usually disappears during adolescence and is rare by adulthood
Figure 7.9
FIGURE 7.9 Test picture like that used to identify children with eidetic imagery. To test your eidetic imagery, look at the picture for 30 seconds. Then look at a blank surface and try to “project” the picture on it. If you have good eidetic imagery, you will be able to see the picture in detail. Return now to the text and try to answer the questions there. (Redrawn from an illustration in Lewis Carroll’s Alice’s Adventures in Wonderland.)
RelearningLearning again something that was previously
learnedUsed to measure memory of prior learning
Savings Score: Amount of time saved when relearning information
ForgettingNonsense Syllables: Meaningless three-letter
words (fej, quf) that test learning and forgettingCurve of Forgetting: Graph that shows the
amount of memorized information remembered after varying lengths of time
Encoding Failure: When a memory was never formed in the first place
Memory Traces: Physical changes in nerve cells or brain activity that occur when memories are stored
Memory Decay: When memory traces become weaker; fading or weakening of memories
Disuse: Theory that memory traces weaken when memories are not used or retrieved often
Figure 7.10
FIGURE 7.10 The curve of forgetting. This graph shows the amount remembered (measured by relearning) after varying lengths of time. Notice how rapidly forgetting occurs. The material learned was nonsense syllables. Forgetting curves for meaningful information also show early losses followed by a long gradual decline, but overall, forgetting occurs much more slowly.
Memory in the courtroom
Additional Theories of ForgettingMemory Cues: Any stimulus associated with a
memory; usually enhance retrieval of a memoryA person will forget if cues are missing at
retrieval timeState-Dependent Learning: When memory
retrieval is influenced by body state; if your body state is the same at the time of learning AND the time of retrieval, retrievals will be improvedIf Robert is drunk and forgets where his car is
parked, it will be easier to recall the location if he gets drunk again!
Figure 7.12
FIGURE 7.12 The effect of mood on memory. Subjects best remembered a list of words when their mood during testing was the same as their mood was when they learned the list.
Even More (!) Theories of ForgettingInterference: Tendency for new memories to
impair retrieval of older memories, and vice versaRetroactive Interference: Tendency for new
memories to interfere with retrieval of old memories
Proactive Interference: Prior learning inhibits (interferes) with recall of later learning
Figure 7.13
FIGURE 7.13 The amount of forgetting after a period of sleep or of being awake. Notice that sleep causes less memory loss than activity that occurs while one is awake.
Figure 7.14
FIGURE 7.14 Effects of interference on memory. A graph of the approximate relationship between percentage recalled and number of different word lists memorized. (Adapted from Underwood, 1957.)
Figure 7.15
FIGURE 7.15 Retroactive and proactive interference. The order of learning and testing shows whether interference is retroactive (backward) or proactive (forward).
More on ForgettingRepression: Unconsciously pushing painful,
embarrassing or threatening memories out of awareness/consciousnessMotivated forgetting, according to some
theoriesSuppression: Consciously putting something
painful or threatening out of mind or trying to keep it from entering awareness
Flashbulb MemoriesMemories created during times of personal
tragedy, accident, or other emotionally significant events that are especially vividWhere were you when you heard that the USA
was attacked on September 11th, 2001?Includes both positive and negative eventsNot always accurateGreat confidence is placed in them even though
they may be inaccurate
Improve Your MemoryStudy repeatedly to boost recallSpend more time rehearsing or
actively thinking about the materialMake material personally
meaningfulUse mnemonic devices
associate with peg words--something already storedchunk information into acronyms
Study in spaced intervals
Improve Your Memory
Activate retrieval cues--mentally recreate situation and mood
Minimize interference Test your own knowledge
to rehearse itto determine what you do not yet know
Déjà vu (似曾相识)
Déjà vu
Scientific explanationsDual processing (2 cognitive processes
momentarily out of synchrony)Neurological (seizure, disruption in neuronal
transmission)Memory (Implicit familiarity of unrecognized
stimuli) and attentional (unattended perception followed by attended perception)