INTERFERENCE IN EPISODIC MEMORY

1. INTERFERENCE IN EPISODIC MEMORY • Causes of forgetting • Interference versus decay • McGeoch (1932) & the triumph of interference • Forgetting and the issue of permanence • Associative Interference in PAL • The Paired-Associate Learning task • What is learned? • Response learning • Stimulus differentiation • Associative hook-up • Item- and list-level knowledge • Retroactive and Proactive interference • The RI and PI designs • Effects of number and strength of competing responses • Effects of retention interval on RI and PI • Effects of type of test

2. Classic PALinterference Designs AB DOG-ROCK CD AC CB DOG-SKY PLAN-ROCK PLAN-SKY DOG:____? DOG: stone sky rock

3. MECHANISMS OF ASSOCIATIVE INTERFERENCE • The main issue: is interference passive (e.g., occlusion), or active (e.g., retrieval inhibition)? • Ineffective routes • Response competition / occlusion • Other associations to cue occlude AB • Is it eliminated in recognition tests? • Is it eliminated in MMFR tests? • Unlearning (for RI designs) • Learning AD weakens AB association • Analogy to extinction in conditioning • Mixed evidence in “recovery” • Ineffective cues • Varied Stimulus Encoding • Learning AD forces differential A encoding • Analogy to encoding specificity effects • Evidence against its role in PAL • Williams & Underwood (1970): XRM cue, X is best for both B and D

4. List-wide interference • Response-set suppression (Postman, Stark & Frasier, 1968) • Inference in the AB,CD paradigm • Independence of item-level recall in AB,AD paradigm • Is it “suppression” or context-change? • Interference in other episodic tasks • Part-set cuing (Slamecka 1968) • Directed forgetting (Bjork et al. 1968) • The DF paradigme.g., Geiselman, Bjork & Fishman ’83) 48 nouns: 1st half mixed “learn” & “judge” Cue to forget or remember 1st half Learn Judge Final recall: F R F R 1st half .56 .73 .30 .45 2nd half .72 .55 .40 .30

5. Explanations of Directed forgetting • Bjork: inhibition / suppression of Forget words (singly or as sublist) • But: no DF effect in recognition • Sahakyan & Kelley (02): “forget” cue as context shift • E1: context-change (“imagine you’re invisible”)No change Change Final recall: F R F R 1st half .30 .40 .24 .30 2nd half .43 .29 .46 .43 • E2: Reinstate initial context at test Reinstated Not Reinstated Final recall: F R+C R F R+C R 1st half: .32 .31 .38 .21 .22 .42 2nd half: .32 .32 .28 .42 .43 .28

6. Inhibition in other domains? • Negative priming effects in naming (Tipper, 85) • Inhibition of return in spatial attention (Posner& Nissen, 1980) • Retrieval effort and inhibition in semantic memory (Dagenbach, 1990) • Ss learn meanings of obscure words • E.g., accipiter: hawk • As primes for related words, these words • Facilitate lexical decision if recalled • But inhibit lexical decision if not (?!) • Suppression of subordinate homograph meanings in long-SOA priming (Burgess & Simpson 1988) • Prime: RING Target: BELL • Facilitates lexical decision at 35 ms SOA • Slows lexical decision at 750 ms SOA • Inhibition of literal meaning response after figurative use (Glucksberg, 1982) • My lawyer is a shark / sharks have skin • Suppression of referents in sentence comprehension (Gernsbacher, 1982) • Ann dropped the box. It / She….

7. Retrieval-Induced Forgetting • (Anderson, Bjork & Bjork 1994) Study: sets of of category-instance pairs FRUIT-orange; FRUIT-apple, etc (n=6)\ TOOL-drill, TOOL-hammer, etc. Cued retrieval practice on half of some categories: FRUIT – or____ Cued-recall test of all pairs RP+ RP- No RP “good” e.g.’s .81 .41 .56 “weak” e.g.’s .66 .35 .41

8. Is it Inhibition? • Anderson et al. (94): high and low taxonomic frequency: Practiced Items nonpracticed items High Low RP+ RP- RP+ RP- High +.16 -.09 +.23 +.04 Low +.17 -.10 +.20 +.09 • Anderson & Spellman (95):cross-cuing paradigm • Some items in one category could be items in another (TOMATO as “RED” or “FOOD” • Results show “cue independent inhibition:”

9. Results of Anderson & Spellman, 95’s independent-probe study:

10. Failure of cross-cue inhibition in PAL: Fischler & Wood (1985) Fist phase: Learn AB, DB pairs RI Phase: Learn AC for half the list pairs Test phase: cued with A, B shows strong interference from AC cued with D, B shows no interference from AC E2: Precued (100 ms) with (A)D, All B responses are slowed

11. Recent developments (SEPA report) • Inhibition in the “no think” paradigm(Anderson, 2005) • Ss learn paired-associates • Retrieval or “no think” practice with exposure to some stimulus words • Within-list inhibition for “no think” pairs • So: item-specific directed forgetting? • “no think” stimuli asssociated with increased DLPFC, decreased hippocampal (contralateral?) activity • Degree of activity correlated with size of inhibitory effect • Extensions of RP effects to eyewitness memory, semantic memory, text, etc. • Some failures to show cue independence, or “strength independence” • Issue of degree of “output interference” as cause of RP- inhibition