Model of Memory

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

2. 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)

3. Some Distinctions in LTM • Endel Tulving: There are two broad categories of information that are represented in LTM - • Episodic Memory: memory of an event in your life • autobiographical • has a temporal context - something about time is encoded along with the memory

4. Some Distinctions in LTM • Endel Tulving: There are two broad categories of information that are represented in LTM - • Semantic Memory: memory of facts, knowledge of the world • unconnected to an autobiographical event • no temporal context

5. Some Distinctions in LTM • There is a third category: • Procedural Memory: memory for actions

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

7. Semantic Memory • Structure of encoding is associative

8. 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

9. 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 or fap) and must respond “word” or “non-word”

10. 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

11. 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

12. Semantic Memory • Structure of encoding is associative • Evidence: Semantic Priming in a Lexical-Decision Task • 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

13. 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

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

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

16. 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.

17. 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

18. 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

19. Recalling Episodic Memory • context is critical! • location, physiological state, etc. affect ability to recall and your confidence that you recalled correctly • e.g. lists of words are recalled better when recalled where they were first learned

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

21. 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

22. 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

23. Implicit and Explicit Memory: yet another distinction • Are all memories explicit? Is all information stored in the brain subject to conscious scrutiny?

24. Implicit and Explicit Memory: yet another distinction • 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

25. Implicit and Explicit Memory: yet another distinction • How can we know whether memory is stored/recalled implicitly or explicitly?

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

27. 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

28. 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

29. 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?

30. 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

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

32. 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

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

34. 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

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

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

37. 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 ______”

38. 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

39. 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

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

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

42. Recalling Episodic Memory • Memory for episodes in life can be illusory

43. Recalling Episodic Memory • Memory for episodes in life can be illusory • Consider the example in Loftus’ article: • participant was induced to have an episodic memory of being lost in a mall

44. Recalling Episodic Memory • Memory for episodes in life can be illusory • Consider the example in Loftus’ article: • participant was induced to have an episodic memory of being lost in a mall • Even when told the memory is a false one, the participant had difficulty recognizing it as an invalid memory

45. Recalling Episodic Memory • False Memories may arise when details of a crime are in question as in eye-witness testimony or repressed memories of abuse during childhood

46. Repressed Memories Elizabeth Loftus

47. “Derepressed memories” • Loftus opens with several examples of court cases that involve “derepressed memories” • What is a repressed memory? • What is a derepressed memory?

48. Loftus’ position in this article • Loftus does not reject the notion of repressed memories • 18% - 59% of abuse survivors report having regained access to previously repressed memories

49. Loftus’ position in this article • Loftus does not reject the notion of repressed memories • 18% - 59% of abuse survivors report having regained access to previously repressed memories • What does Loftus challenge?

50. Loftus’ position in this article • Loftus does not reject the notion of repressed memories • 18% - 59% of abuse survivors report having regained access to previously repressed memories • What does Loftus challenge? …That all “de-repressed” memories are accurate memories.