The Nature of Memory

1. The Nature of Memory Making Memories

2. Distinct Memory Systems • Episodic • Personal or W W W • Semantic • General Information and Meaning • Procedural • “Doing” versus “Saying”

3. Game Shows and Memory Systems

4. Biological Evidence • Episodic Memory Loss • “Clive Wearing” • New Memories Lost (Episodic and Semantic) • “H.M.” • Procedural Memory Loss • Parkinson’s / Depression

5. Back

6. H.M. and Memory (Hippocampus) Back

7. Brain Structures Procedural Memory Basal Ganglia

8. Memory Processing

9. Three Stages of Processing for Non- Procedural Memories

10. Short-Term (STM) and Long Term (LTM) Baddeley (2003)

11. Sensory Memory • Briefly holds information • Experience constant flow • Select important information • Remainder fades quickly • Duration • Visual < 2 seconds • Auditory < 5 seconds

12. Sperling’s Experiment Whole Report: Four or five letters of twelve Partial Report: All four letters in row

13. Auditory STM (Phonological Loop) • Lasts about 18 seconds without rehearsal • Contains 7 items on average • Language self-talk • Two components: maintenance (rehearsal) and manipulation (elaboration).

14. Forgetting in Auditory STM

15. Forgetting inAuditory STM

16. In Class Slide

17. Capacity of Auditory STM • Immediate Memory Span: Maximum number of items one can recall after one presentation. • Miller’s (1956) “Magic Number”: 7 plus or minus 2 chunks of information.

18. In Class Slide

19. Chunking in STM • Chunks are meaningful groups. • Bigger chunks expand STM. • Digit span can be increased. • Expert memory for chess positions

20. Rehearsal Errors in STM

21. Levels-of-Processing(STM into LTM) • Memory depends on how deeply the information is processed. • Maintenance Rehearsal: Encode and process information through repetition (shallow). • Elaborative Rehearsal: Encode and process information by relating new material to information already stored in memory (deep).

22. In Class Slide

23. Serial-Position Curve

24. Long-Term Memory (LTM) • Relatively Permanent • Semantic, Episodic, or Procedural • Subject to distortion (your memory is not a DVD recorder) • Retrieval Failures Cause “Forgetting”

25. Intentional andUnintentional Memories • Explicit memory is the deliberate attempt to remember something. • Implicit memory is the unintentional recollection or influence of a prior experience.

26. Do We Forget? • Hermann Ebbinghaus first to study memory and forgetting in late 1800s. • Devised the method of savings. • Two lasting discoveries: • Shape of the forgetting curve. • Found long-lasting “savings” in long term memory. Continue

27. Ebbinghaus’ Forgetting Curve Return

28. How Do We Forget? • Decay: The gradual inability to retrieve information from memory. • Interference: Either the storage or retrieval of information is impaired by the presence of other information. • Retroactive Interference: Interference from information learned AFTER • Proactive Interference: Interference from information learned BEFORE

29. Procedures forStudying Interference

30. Encoding Specificity: Effectiveness of retrieval depends on how the information was encoded. Learning (Imagine) Visual Test Rhyme Test Incidental Test

31. Other Types of Specificity • Context-Dependent Memory: Helped by a similarity in physical context at retrieval • State-Dependent Memory: Helped by a similarity in person’s internal state at retrieval. • Transfer-Appropriate Memory: Helped by a similarity in the mental process used at retrieval

32. Retrieval Cues

33. Retrieval from Semantic Memory • Semantic memory network theories suggest that information is retrieved through the principle of spreading activation.

34. Semantic Memory Networks

35. Can lead to: • Tip-of-the-tongue phenomenon is an example of incomplete knowledge. • False Memories • Demo

36. In Class Slide

37. Improving Memory

38. Mnemonics • Putting information into an organized context • Verbal organization: (Catchy schemes) • Method of Loci: One imagines each item occupying a place within a set of familiar locations.

39. Retrieval From Episodic Memory • Memory formation affected by not only what we perceived, but also by what we already know. • Existing knowledge is used to organize new information as we receive it.

40. Distortions of Episodic LTM • Where were you? • Example: Schmolck, Buffalo, & Squire (2000)

41. Schmolck et al.

42. Schemas • Mental representations of categories of objects, events, and people. • Schemas provide a basis for making inferences about incoming information during the encoding stage.

43. Schemas and Recall

44. Eyewitness Testimony • How accurate is eyewitness memory? • Compelling evidence, but eyewitnesses make many mistakes. • Eyewitnesses can only remember what they attended to. • Limits to how valid their reports can be.

45. Some Influences on Eyewitness Memory

46. Eyewitness Testimony (cont’d) • Jurors’ belief influenced by the witness. • But, extremely detailed testimony does not guarantee accuracy. • Jurors tend to believe confident witnesses • But, witnesses’ confidence higher than their accuracy.

47. Eyewitness Testimony (cont’d) • Weaknesses in eyewitness testimony amplified by: • Source Amnesia: Remembering past choice not actual event (police line-ups). • Reconsolidation: Act of remembering changes memory • Recovery Memories • Repression (weak evidence) • Motivated Forgetting (strong evidence) • Implanted Memories (strong evidence)