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Core Features of Episodic Memory (1) Memory for specific events from your past
(2) Involves retrieving the bound together contents and context (what happened, when it happened and where did it happen)
(3) Associated with a particular kind of conscious experience ‘mental time travel’ re-experiencing past sights, sounds, etc
Episodic Memory Mechanisms
ConsolidationMechanisms
AttentionalControl
Encoding Storage Retrieval
AttentionalControl
SemanticRecords
PerceptualRecords
Binding
ContextSemanticRecords
PerceptualRecords
Binding
Context
Aims of Lecture 3
(1) How the core features are investigated in lab-based experiments that strip EM down to its basic elements.
(2) How does EM differ from other forms of long term memory?
(3) What don’t we know about episodic memory?
Amnesia
Past Future
RetrogradeAnterograde
Vargha-Khadem et al, Science (1997)Three amnesic children
Beth: birth: perinatal anoxic episode, seizuresJon: age 4: seizuresKate: age 9: drug overdose, inducing seizures
Disabling memory problems with every-day lifeSpatio-temporal (i.e. Episodic!)
But ‘normal’ intellectual development
Childhood (Anterograde) Amnesia
(1) What kind of brain damage was present?
(2) What kind of memory has been lost?» Which cognitive processes are no longer functioning?
(3) What kind of memory is still intact?
Questions Asked by Varga-Khadem
Functional brain imaging to reveal brain damage
Standard neuropsychological tests of general intellectual and memory function to establish the clinical profile
Experimental Cognitive Tests of item and associative recognition
Methods Used by Varga-Khadem et al
Selective bilateral (left and right) atrophy of the hippocampal formation
Common Underlying Brain Damage
Speech, language, IQ, etc, all within normal range Immediate recall normal (intact short term working
memory) Delayed recall severely impaired
A clinical profile consistent with a dense and selective anterograde amnesia
Standard Neuropsychological Tests of Intellectual and Memory Functions
Item and associative recognition for
Nonwords (eg FLUNT)FacesNonword pairsFace pairsVoice-face pairsObject-place pairs
Experimental Cognitive Tests of Memory
Study Phase
TOP
TIME
SHOE
CAT
BLUE
DROP
Recognition Test Phase
TIME
SHE
DOG
BLUE
AIR
TOP
NEW!
Performance on theCognitive Tests of Memory
TYPE OF STUDY ITEM ITEMRECOGNITION
ASSOCIATIVERECOGNITION
Nonwords INTACT INTACTFaces INTACT INTACT
Object-place pairs --- IMPAIREDVoice-face pairs ---- IMPAIRED
Selective and generalised loss of episodic memory function» The episodic memory failure may reflect an
inability to bind (associate) qualitatively different kinds of information together.
Intact ability to recognise must be based on a non-episodic form of memory.
General Conclusions
Core Features of Episodic Memory
(1) Memory for specific events from your past
(2) Involves retrieving the bound together contents and context (what happened, when it happened and where did it happen)
(3) Associated with a particular kind of conscious experience ‘mental time travel’ re-experiencing past sights, sounds, etc
Episodic Memory Mechanisms
ConsolidationMechanisms
AttentionalControl
Encoding Storage Retrieval
AttentionalControl
SemanticRecords
PerceptualRecords
Binding
ContextSemanticRecords
PerceptualRecords
Binding
Context
Encoding Specificity
How are memory traces accessed by retrieval ‘cues’?» Introduced by Tulving and Thompson, in 1973.
The most effective ‘retrieval pathways’ reinstate processing that occurred when the target information was encountered.
How Encoding Specificity Works
From Fisher and Craik (1976) (see Reisberg, pp176-177)
» Subjects studied word-pairs – The encoding task emphasised a relationship based either on
meaning (‘CAT-DOG’) or on sound (‘CAT-HAT’)
» And performed ‘associative recall’ tasks– Can you recall a studied word associated with ‘CAT’?
– Can you recall a studied word sounding like ‘CAT’?
Fisher and Craik’s Findings
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2025
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ENCODEMEANING
ENCODE SOUND
MEANING CUE
SOUND CUE
Various Encoding Specificity Effects
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20
25
30
35
40
ENCODE ONLAND
ENCODEUNDERWATER
RETRIEVE ONLAND
RETRIEVEUNDERWATER
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20
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50
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90
SAD ENCODING HAPPYENCODING
SAD RETRIEVAL
HAPPYRETRIEVAL
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10
15
2025
30
35
40
45
50
ENCODEMEANING
ENCODE SOUND
MEANING CUE
SOUND CUE
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5
10
15
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PLACEBOENCODING
DOPE ENCODING
PLACEBORETRIEVAL
DOPERETRIEVAL
Encoding Specificity
Memory performance is best when there is overlap in the conditions at encoding and retrieval.
Nothing is encoded in isolation, information is always encoded within a ‘context’, including» The external spatiotemporal context (time and place)
» Your internal thoughts and feelings while the information is processed.
Episodic Memory Mechanisms
ConsolidationMechanisms
AttentionalControl
Encoding Storage Retrieval
AttentionalControl
SemanticRecords
PerceptualRecords
Binding
ContextSemanticRecords
PerceptualRecords
Binding
Context
Core Features of Episodic Memory (1) Memory for specific events from your past
(2) Involves retrieving the bound together contents and context (what happened, when it happened and where did it happen)
(3) Associated with a particular kind of conscious experience ‘mental time travel’ re-experiencing past sights, sounds, etc
His face is familiar...
When episodic memory fails.....
HEY BUDDY,I MISSED YOUSO MUCH....
Recollection Contrasted With Familiarity
Only recollection, the retrieval of episodic details, can provide information about the ‘source’ of a memory.
Familiarity can arise for a number of reasons, and can support recognition judgements even when recollection fails - hence it can be prone to error.
It is possible that Varga-Khadem’s patients may have been utilising the familiarity of studied items as a basis for their intact recognitions.
Modified Recognition Procedures
Remember / Know Judgements» Ask subjects to report on their experiences while recognising.
» Do they ‘Remember’ any episodic details
» Or do they just ‘know’ the information was encountered at study.
These cognitive processes supporting remember and know responses are not identical. » E.g. only ‘remember’ responses are reduced when attention is
divided.