Properties of STM

1. Properties of STM • Short (scale of seconds) • Limited capacity • Attentive • Primacy • Recency • Interference (complex and specific)

2. A Modular Approach to STM Central Executive Articulatory Loop Visuospatial Sketchpad Experiment 1 in the article by Lee Brooks demonstrates a double dissociation between Articulatory Loop and Visuospatial Sketchpad

3. Model of Memory RETRIEVAL Turning now to Long-Term Memory ATTENTION Sensory Memory Short-Term Memory Long-Term Memory Sensory Signals REHEARSAL

4. Long-Term Memory • Characteristics (intuitive with some introspection): • Persists indefinitely (up to decades!) • Requires no active process of rehearsal (at least that we are conscious of)

5. Some Distinctions in LTM • Declarative • Declarative memory is for the sort of information that can become explicit – facts (semantic), autobiographical events (episodic). • The term explicit memory is often associated to convey that such memories are accessible to conscious awareness.

6. Some Distinctions in LTM • Non-Declarative • Non-declarative memory is for the sort of information that is used without explicit awareness – how to do an action (procedural) • Implicit memory is when behaviour is influenced in the absence of conscious memory.

7. Some Distinctions in LTM • Declarative Memory • Episodic Memory: memory of an event in your life • autobiographical • has a temporal context - something about time is encoded along with the memory

8. Some Distinctions in LTM • Declarative Memory • Semantic Memory: memory of facts, knowledge of the world • unconnected to an autobiographical event • no temporal context

10. Some Distinctions in LTM • Procedural Memory: memory for actions

11. Semantic Memory • Capacity is huge (unlimited?)

12. Semantic Memory • Structure of encoding is associative

13. Semantic Memory • Structure of encoding is associative • Evidence: Semantic Priming in a Lexical-Decision Task • Priming: prior exposure to some stimulus modifies subsequent processing of a target

14. Semantic Memory • Structure of encoding is associative • Evidence: Semantic Priming in a Lexical-Decision Task • Lexical Decision Task: Subject is shown a target word or pronounceable non-word (eg. gap orbap) and must respond “word” or “non-word”

15. Semantic Memory • Structure of encoding is associative • Evidence: Semantic Priming in a Lexical-Decision Task • manipulation: prime can be either related or unrelated to the target word

16. Semantic Memory • Structure of encoding is associative • Evidence: Semantic Priming in a Lexical-Decision Task • result: words are identified faster when preceded by a semantically related prime Prime + Target = Response “space” “gap” fast “truck” “gap” slow

17. Semantic Memory • Structure of encoding is associative • Other evidence: memory can be triggered by recalling related facts

18. Semantic Memory • Structure of encoding is associative • Interpretation: • the representation of information in semantic memory is associative: • each fact or piece of knowledge is stored along with its relationship to other stored information • related items can activate each other which facilitates recall

19. Episodic Memory • Memory for an episode or event in your own life • Has temporal context (entails a sense of duration and date) • examples: • recall breakfast • what happened this weekend

20. Recalling Episodic Memory • Recall is highly sensitive to context - Similarities in context (especially smell) can trigger vivid recollections

21. Recalling Episodic Memory • Memory is affected by the nature of your engagement with the information • Levels-of-Processing Theory

22. Recalling Episodic Memory • Memory is affected by the nature of your engagement with the information • Levels-of-Processing Theory • Consider this experiment: List CAT pie PILLOW TREE • Method of Learning • stating capitals or lower-case • repeating words • putting words into a sentence Recall is tested some time later.

23. Recalling Episodic Memory • Memory is affected by the nature of your engagement with the information • Levels-of-Processing Theory • Consider this experiment: List CAT pie PILLOW TREE • Result: • Best recall with “deep” processing • Worst recall with “surface” processing

24. Recalling Episodic Memory • Memory is affected by the nature of your engagement with the information • Interpretation: • the successful use of memory depends on the number of connections that are made between related items and the degree to which these are initially activated

25. Hypermnesia - S. • “Photographic” extreme memory ability (a mnemonist) • Able to recall complex test stimuli

26. Hypermnesia - S. • S. used two “strategies” or abilities typical of mnemonists: • Rich synesthesia-like quality to his perception of stimuli - leads to stronger associative links

27. Hypermnesia - S. • S. used two “strategies” or abilities typical of mnemonists: • Rich synesthesia-like quality to his perception of stimuli - leads to stronger associative links • Vivid and elaborate mental imagery of things he should remember

28. Hypermnesia - S. • “ Even numbers remind me of images. Take the number 1. This is a proud, well-built man; 2 is a high-spirited woman; 3 a gloomy person (shy, I don’t Know); 6 a man with a swollen foot...” Luria, A.R. The mind of a mnemonist. 1968 Luria, A.R. The man with a shattered world. 1972

29. When You Don’t Remember • Two reasons why you don’t remember:

30. When You Don’t Remember • Two reasons why you don’t remember: • Unavailable • It wasn’t successfully encoded - something went wrong while you were studying

31. When You Don’t Remember • Two reasons why you don’t remember: • Unavailable • It wasn’t successfully encoded - something went wrong while you were studying • Inaccessible • memory is stored but cannot be retrieved, perhaps because appropriate connections aren’t being made

32. Implicit and Explicit Memory • Are all memories explicit? Is all information stored in the brain subject to conscious scrutiny?

33. Implicit and Explicit Memory • Are all memories explicit? Is all information stored in the brain subject to conscious scrutiny? • Implicit Memory refers to encoded memories that are not part of the “contents” of awareness

34. Implicit and Explicit Memory • How can we know whether memory is stored/recalled implicitly or explicitly?

35. Implicit Memory • Consider the following distinction in recalling items from a list of words:

36. Implicit Memory • Consider the following distinction in recalling items from a list of words: • Free Recall - subjects can be asked to simply recall and report as many items as possible - these items are accessible as explicit memory

37. Implicit Memory • Consider the following distinction in recalling items from a list of words: • Implicit Recall - subjects can be asked to complete a word stem with any word that comes to mind after reading a list of words (no mention of testing memory!) __ack

38. Implicit Memory • Consider the following distinction in recalling items from a list of words: • Implicit Recall - subjects can be asked to complete a word stem with any word that comes to mind after reading a list of words (no mention of testing memory!) But how do you know that information is stored/recalled implicitly? Couldn’t it be explicit?

39. Implicit Memory • Consider the following distinction in recalling items from a list of words: • Twist - require subject to complete stem with a word that wasn’t on the list - if a word from the list is used preferentially, it was remembered implicitly

40. Implicit Memory Consider the implications regarding the nature of consciousness and the connection between neural activity and awareness

41. Implicit Memory Consider the implications regarding the nature of consciousness and the connection between neural activity and awareness Not all of the activity in your brain generates experience - some is “sub”conscious or non-conscious

42. Recalling Episodic Memory • Recall is a generative processes rather than simply calling up stored data

43. Recalling Episodic Memory • Recall is a generative processes rather than simply calling up stored data • Evidenced by the fact that episodic memories can be distorted or completely false under certain circumstances

44. Recalling Episodic Memory • Misinformation Effect - exposure to information subsequent to storage of memory can alter the contents of the memory

45. Recalling Episodic Memory • Misinformation Effect • Consider the following example: • Subjects were shown a video depicting a car accident

46. Recalling Episodic Memory • Misinformation Effect • Consider the following example: • Subjects were shown a video depicting a car accident • Then given the following question: “How fast were the vehicles going when they ______”

47. Recalling Episodic Memory • Misinformation Effect • Consider the following example: • Subjects were shown a video depicting a car accident • Then given the following question: “How fast were the vehicles going when they ______” • Different subjects were asked questions that differed in the “magnitude” of the final word

48. Recalling Episodic Memory • Misinformation Effect • Consider the following example: • Subjects were shown a video depicting a car accident • Then given the following question: “How fast were the vehicles going when they ______” • Different subjects were asked questions that differed in the “magnitude” of the final word • The possible words were: Contacted, Hit, Bumped, Collided, and Smashed

49. Recalling Episodic Memory • Misinformation Effect • Consider the following example: • Average estimated velocity depended on the nature of the question

50. Recalling Episodic Memory • Misinformation Effect • Interpretation: • Episodic memory can be distorted by subsequent information