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Core Features of Episodic Memory l (1) Memory for specific events from your past l (2) Involves retrieving the bound together contents and context (what.

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Presentation on theme: "Core Features of Episodic Memory l (1) Memory for specific events from your past l (2) Involves retrieving the bound together contents and context (what."— Presentation transcript:

1 Core Features of Episodic Memory l (1) Memory for specific events from your past l (2) Involves retrieving the bound together contents and context (what happened, when it happened and where did it happen) l (3) Associated with a particular kind of conscious experience l mental time travel l re-experiencing past sights, sounds, etc

2 Episodic Memory Mechanisms Consolidation Mechanisms Attentional Control EncodingStorageRetrieval Attentional Control Semantic Records Perceptual Records Binding Context Semantic Records Perceptual Records Binding Context

3 Aims of Lecture 3 l (1) How the core features are investigated in lab-based experiments that strip EM down to its basic elements. l (2) How does EM differ from other forms of long term memory? l (3) What dont we know about episodic memory?

4 Amnesia PastFuture RetrogradeAnterograde

5 l Vargha-Khadem et al, Science (1997) l Three amnesic children l Beth: birth: perinatal anoxic episode, seizures l Jon: age 4: seizures l Kate: age 9: drug overdose, inducing seizures l Disabling memory problems with every-day life l Spatio-temporal (i.e. Episodic!) l But normal intellectual development Childhood (Anterograde) Amnesia

6 l (1) What kind of brain damage was present? l (2) What kind of memory has been lost? »Which cognitive processes are no longer functioning? l (3) What kind of memory is still intact? Questions Asked by Varga-Khadem

7 l Functional brain imaging to reveal brain damage l Standard neuropsychological tests of general intellectual and memory function to establish the clinical profile l Experimental Cognitive Tests of item and associative recognition Methods Used by Varga-Khadem et al

8 l Selective bilateral (left and right) atrophy of the hippocampal formation Common Underlying Brain Damage

9 l Speech, language, IQ, etc, all within normal range l Immediate recall normal (intact short term working memory) l Delayed recall severely impaired l A clinical profile consistent with a dense and selective anterograde amnesia Standard Neuropsychological Tests of Intellectual and Memory Functions

10 l Item and associative recognition for l Nonwords (eg FLUNT) l Faces l Nonword pairs l Face pairs l Voice-face pairs l Object-place pairs Experimental Cognitive Tests of Memory

11 Study Phase TIME SHOE CAT BLUE DROP

12 Recognition Test Phase TIME SHE DOG BLUE AIR NEW!

13 Performance on the Cognitive Tests of Memory

14 l 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. l Intact ability to recognise must be based on a non- episodic form of memory. General Conclusions

15 Core Features of Episodic Memory l (1) Memory for specific events from your past l (2) Involves retrieving the bound together contents and context (what happened, when it happened and where did it happen) l (3) Associated with a particular kind of conscious experience l mental time travel l re-experiencing past sights, sounds, etc

16 Episodic Memory Mechanisms Consolidation Mechanisms Attentional Control EncodingStorageRetrieval Attentional Control Semantic Records Perceptual Records Binding Context Semantic Records Perceptual Records Binding Context

17 Encoding Specificity l How are memory traces accessed by retrieval cues? »Introduced by Tulving and Thompson, in l The most effective retrieval pathways reinstate processing that occurred when the target information was encountered.

18 How Encoding Specificity Works l From Fisher and Craik (1976) (see Reisberg, pp ) »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?

19 Fisher and Craiks Findings

20 Various Encoding Specificity Effects

21 Encoding Specificity l Memory performance is best when there is overlap in the conditions at encoding and retrieval. l 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.

22 Episodic Memory Mechanisms Consolidation Mechanisms Attentional Control EncodingStorageRetrieval Attentional Control Semantic Records Perceptual Records Binding Context Semantic Records Perceptual Records Binding Context

23 Core Features of Episodic Memory l (1) Memory for specific events from your past l (2) Involves retrieving the bound together contents and context (what happened, when it happened and where did it happen) l (3) Associated with a particular kind of conscious experience l mental time travel l re-experiencing past sights, sounds, etc

24 His face is familiar... When episodic memory fails..... HEY BUDDY, I MISSED YOU SO MUCH....

25

26 Recollection Contrasted With Familiarity l Only recollection, the retrieval of episodic details, can provide information about the source of a memory. l Familiarity can arise for a number of reasons, and can support recognition judgements even when recollection fails - hence it can be prone to error. l It is possible that Varga-Khadems patients may have been utilising the familiarity of studied items as a basis for their intact recognitions.

27 Modified Recognition Procedures l 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. l These cognitive processes supporting remember and know responses are not identical. »E.g. only remember responses are reduced when attention is divided.


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