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Lecture 6 – Psyco 350, B1 Winter, 2011

Lecture 6 – Psyco 350, B1 Winter, 2011. N. R. Brown. Outline. An Alternative Perspectives on WM Reading& Operation Span tasks Cowan’s Embedded Processes Mode WM Capacity as Executive Control LTM: Episodic-Semantic Distinction Memory Basics: Concepts & Associations (nodes & links)

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Lecture 6 – Psyco 350, B1 Winter, 2011

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  1. Lecture 6 – Psyco 350, B1Winter, 2011 N. R. Brown Psyco 350 Lec #6 – Slide 1

  2. Outline • An Alternative Perspectives on WM • Reading& Operation Span tasks • Cowan’s Embedded Processes Mode • WM Capacity as Executive Control • LTM: Episodic-Semantic Distinction • Memory Basics: Concepts & Associations (nodes & links) • Factors that influence Storage: • Rehearsal • maintenance vs elaborate • massed vs spaced Psyco 350 Lec #6 – Slide 2

  3. Alternatives Perspectives On WM Motivated by: • Problems w/ Baddeley’s Model • A need to better understand executive functioning • Predictive power of span task. Three Related Issue • Reading/Operation Span as a measure of “capacity” • WM contents as the active portion of LTM • WM as executive attention Psyco 350 Lec #6 – Slide 3

  4. Measuring WM Capacity • Key Idea: Performance on complex cognitive task reflects a number of different capacities • retrieval efficiency • processing efficiency • “attention-free” capacity of relevant slave system • attentional management (ability to focus on relevant info & inhibit irrelevant info. • etc. • WM span tasks developed to measure relation between WM and performance on complex cognitive tasks Psyco 350 Lec #5 – Slide 4

  5. WM Memory Span • WM span = # of words recalled • Demonstrates capacity for holding load while processing. • Large individual differences in WM span (2-6 items) • WM span measures predict performance on IQ, achievement tests (e.g., SATs), & g. • digit/word span uncorrelated with IQ/SAT tests Psyco 350 Lec #6 – Slide 5

  6. WM Memory Span – Two Interpretations • Domain Specific Capacity: Efficient processing of immediate task, leaves additional resources for maintaining load. • Accounts for dual task performance (e.g. Brooks) • Domain General Capacity: General ability to “control attention to maintain information in anactive quickly retrievable state.” Engle, 2009, p. 20. Psyco 350 Lec #6 – Slide 6

  7. An Alternative: WM as Information in an Active State Psyco 350 Lec #6 – Slide 7

  8. WM as Activation: Cowan’s Embedded Processes Model • Central Executive: directs and controls voluntary processing. • Encoding: • Incoming info activities representation in LTM Psyco 350 Lec #6 – Slide 8

  9. WM as Activation: Cowan’s Embedded Processes Model Central Notation: LTM in one of 3 states: • Dormant • Activated • fades (decays) unless reactivated • “In focus” (of attention) • limited to 4 items Psyco 350 Lec #6 – Slide 9

  10. Span from Activation Perspective Two components: • read-out from focus • activated material, retrieved before decay Predictions: • factors  LTM,  span • concreteness (Walker & Hulme, 1999) • word frequency (Roodenrys & Quinlan, 2000) • Span > 0 when rehearsal suppressed Psyco 350 Lec #6 – Slide 10

  11. WM Memory Span – Competing Interpretations • Domain Specific Capacity: Efficient processing of immediate task, leaves additional resources for maintaining load. Accounts for Dual-task • Domain General Capacity: General ability to “control attention to maintain information in anactive quickly retrievable state.” Engle, 2009, p. 20. Psyco 350 Lec #6 – Slide 11

  12. Span as Executive Control Main Idea: • Active, irrelevant info infers w/ performance • People differ in their ability to inhibited irrelevant info or remain focused on relevant info Prediction: Individual differences in reading/operation span predict performance on tasks that require executive control. Psyco 350 Lec #6 – Slide 12

  13. Three Lines of EvidenceSpan & Proactive Interference Participants: High-span Low-span Materials & procedure: 3 10-word lists (words from same category) 2 s/word 16 s Delay 20 s recall periods Psyco 350 Lec #6 – Slide 13

  14. Three Lines of EvidenceSpan & Proactive Interference Results: • Proactive Interference • PI worse for Low-span Psyco 350 Lec #6 – Slide 14

  15. Three Lines of EvidenceSpan & Anti-saccade TasK Task: Move eyes away from cue to find taget Measures: Distractibility Main Finding: Low Span worse (more distractible) than High-span Psyco 350 Lec #6 – Slide 15

  16. Three Lines of EvidenceSpan & The Stroop Task • StroopTask – Name Color of font Psyco 350 Lec #6 – Slide 16

  17. Three Lines of EvidenceSpan & The Stroop Task • StroopTask – Name color of font • General Finding: Incongruent trials (BLUE) slower than congruent trials (GREEN) • Interpretation: Response slowed because attention required to inhibit color name. Psyco 350 Lec #6 – Slide 17

  18. Three Lines of EvidenceSpan & The Stroop Task Participants: Low Span Vs High SP Materials: Congruence: 0%, 50%, 75% Difficulty increases w/ congruence Psyco 350 Lec #6 – Slide 18

  19. Three Lines of EvidenceSpan & The Stroop Task Results: • Difficulty increases w/ congruence • Low-span worse than High-span • Effect increase w/ congruence Interpretation: Inhibitory capacity particularly important when task is difficult. Psyco 350 Lec #6 – Slide 19

  20. WM Capacity as Executive Attention Engle (2009) Main Claim: WM capacity (as measure by reading & operation span) reflect individual differences in ability inhibit/exclude competing (partially active) sources of information. Psyco 350 Lec #6 – Slide 20

  21. Summary: Alternative View Contents of WM Active portion of LTM Differences in Capacity Reflects individual differences in ability to remain focused and inhibit irrelevant info. Reflect in LTM and task perceptual tasks Psyco 350 Lec #6 – Slide 21

  22. Conclusions • No pure measure of STM • Contents: focal info + activated LTM • Covert Rehearsal: • one way of keeping info active • Functional importance: • WM provides ability to access info and maintain in active state required for thought, language, problem-solving, etc Psyco 350 Lec #6 – Slide 22

  23. Procedural • Knowing how Declarative • Knowing that Memory Systems Procedural Declarative Episodic Semantic Psyco 350 Lec #6 – Slide 23

  24. Episodic-Semantic Distinction: Tulving (1972) Episodic Memory: • autobiographical • temporally dated • interference from similar episodes • retrieval also serves as input (i.e., episodic memory is continually being updated) Psyco 350 Lec #6 – Slide 24

  25. Episodic-Semantic Distinction Tulving (1972) Semantic Memory: • language (lexical memory) • world knowledge • not temporally dated • very well-organized (organization protects memory from interference) • not changed or modified by retrieval of information (i.e., not continually updated) Psyco 350 Lec #6 – Slide 25

  26. (Episodic) Memory Basics • Content episodic memory • representation of specific events • mini-events – “the work BOOK on List 2” • real events – “Diving in Cozumel” • An event representation (ER) = a particular instantiation of a configuration of intersecting concepts Psyco 350 Lec #6 – Slide 26

  27. Memory Trace: “the word BOOK on List 2” WM BOOK List 2 SM Event34272 EM Psyco 350 Lec #6 – Slide 27

  28. Memory Trace: “Diving in Cozumel” WM Cozumel Diving SM Event20342 EP Psyco 350 Lec #6 – Slide 28

  29. (Episodic) Memory Basics • Links between ER & concepts differ in strength (as do the links between concepts). • Strength depends of: • frequency • contiguity • recency Psyco 350 Lec #6 – Slide 29

  30. (Episodic) Memory Basics • Cues in WM access conceptual information in LTM. • Origin of cues: • environment • self-generated • provided by experimenter • Concepts “spread activation” to linked nodes (other concepts & ERs) • ERn activation > threshold, “ERn retrieved” Psyco 350 Lec #6 – Slide 30

  31. Cue word: “Cozumel” “Cozumel” WM Cozumel Diving SM Event20342 EP Psyco 350 Lec #6 – Slide 31

  32. (Episodic) Memory Basic: Implications • The stronger the link between a cued concept and an ER, the greater probability that the ER will be recalled. [non-elaborative rehearsal] Psyco 350 Lec #6 – Slide 32

  33. Cue word: Cozumel w/ strong link “Cozumel” WM Cozumel Diving SM Event20342 EP Psyco 350 Lec #6 – Slide 33

  34. (Episodic) Memory Basic: Implications • The more ER-to-concept links there are, the greater the probability that a given cue will serve as an effective retrieval cue. [elaboration, depth or processing] Psyco 350 Lec #6 – Slide 34

  35. Cue words: “Cozumel” “diving” “hurricane” WM hurricane Cozumel Diving SM Event20342 EP Psyco 350 Lec #6 – Slide 35

  36. (Episodic) Memory Basic: Implications • Context (internal & external) is encoded as part of the ER, and thus contextual features can serve as retrieval cues. • Increasing the similarity between encoding contexts and retrieval contexts increases the probability of retrieval. [context effects, TAP] Psyco 350 Lec #6 – Slide 36

  37. Contextual Cue taste of t. scrimp WM Cozumel Diving tequila scrimp SM Event20342 EP Psyco 350 Lec #6 – Slide 37

  38. (Episodic) Memory Basic: Implications • Probability of recall decreases, as # of ERs linked to a cued concept increases. [interference] Psyco 350 Lec #6 – Slide 38

  39. Cue word: “diving”  interference “diving” WM Cozumel Diving Grand Banks SM Event20342 Event5632 EP Psyco 350 Lec #6 – Slide 39

  40. Memory Processes • Encoding: • process of storing information in memory • Storage: • the retention (& loss) of information over time • Retrieval: • recovery of previously stored information Psyco 350 Lec #6 – Slide 40

  41. Encoding Processes: Rehearsal • Rehearsal: a set of techniques/strategies for encoding information into long-term memory • Two kinds of rehearsal: • Maintenance: keeps information "alive" in WM; rote recycling; little effect on LTM • Elaboration: "promotes" information to LTM; think about and connect Psyco 350 Lec #6 – Slide 41

  42. Maintenance Rehearsal:Craik and Watkins (1973) Task: • Monitor auditory list for words beginning w/ target letter (e.g., G) • required to recall “last” target word at end of list (list could end at any time). • Session final recall – recall as many words as possible. Manipulation: # of words between appearance of target word (assumed equal to amount of rehearsal). Psyco 350 Lec #6 – Slide 42

  43. Craik & Watkins (1973) Results: • recall unaffected by # of rehearsals. Interpretation: rote (maintenance) rehearsal fails to transfer info to LTM. Question: • What about Rundus (1971)? • Maintenance + (elaboration, relational coding, etc) Psyco 350 Lec #6 – Slide 43

  44. Rundus (1971) again • Analysis: • # rehearsals for each word (position) • % recall for each word (position) • Results: • “For a given amount of rehearsal, items from the initial serial positions are no better recalled than items from the middle of the list” – Rundus, 1971, p. 66 Psyco 350 Lec #6 – Slide 44

  45. Elaborative Encoding: Bradshaw & Anderson(1982) Tasks: Recall “target” fact Design: Encoding Context X Delay target only immediate (no delay) target + 2 irrelevant facts 1 week target + 2 relevant facts Psyco 350 Lec #6 – Slide 45

  46. Elaborative Encoding: Bradshaw & Anderson(1982) Target only: Newton became emotionally unstable and insecure as child. Target+2 irrelevant facts: Locke was unhappy as a student at Westminster. plus Locke felt fruits were unwholesome for children. Locke had a long history of back problems. Target+2 relevant facts Mozart made a long journey form Munich to Paris. plus Mozart wanted to leave Munich to avoid a romantic entanglement. Mozart was intrigued by musical developments in Paris. Psyco 350 Lec #6 – Slide 46

  47. Bradshaw & Anderson(1982): Results • Encoding relevant facts improved recall. • Encoding irrelevant facts hampered recall. • Effect was magnified by delay. Interpretation: • relevant elaboration increases # of retrieval path • relevant facts fosters generation of appropriate cues • irrelevant facts cause interference Psyco 350 Lec #6 – Slide 47

  48. Spacing Effects • Issue: • Rehearsal improves memory. • Does the temporal distribution of rehearsals matter? • Research Strategy • holding # of presentations constant, manipulate the lag (delay) between presentations. Psyco 350 Lec #6 – Slide 48

  49. Madigan (1969): Spacing Effect • Method: • words studied twice at 6 different lags. • Results: • recall  w/ lag • Other findings: • spacing affects recognition (Glenberg, 1979) • obtained w/ textbook materials Psyco 350 Lec #6 – Slide 49

  50. Accounting for the Spacing Effect • Deficient Processing • habituate to recently presented material (less “interesting”) • short lags  overestimation of learning --> decreases (or redistributed) rehearsals. • Encoding Variability: • Recall depends in part on study context matching test context. • Context changes w/ time • the greater the lag, the more different the encoding contexts, and therefore the more likely that one of them will overlap with the test context. Psyco 350 Lec #6 – Slide 50

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