Memory Implicit memory PSY 368 Human Memory Memory Implicit memory

Outline Implicit versus explicit memory Process-dissociation procedure Definitions Dissociations Process-dissociation procedure Theories accounting for Implicit vs. Explicit memory

Demo PDP exercise Pass out sheets and read instructions Collecting the data: count up number of study words that were written down for each task, write this on your sheet Pleasantness Vowels Inclusion Exclusion

Questions to Think About Does the type of memory test matter? We’ve seen that the answer is yes. So far have covered intentional vs. incidental, and recall vs. recognition. These have largely been what are considered direct tests of memory (know that it is a memory test related to something earlier). There are also indirect tests of memory (don’t know that the test is related to memory/to something done earlier)

Memory Tasks Test Instructions Study Instructions indirect direct incidental implicit memory expts. Levels of Processing intentional ? explicit memory Study Instructions Implicit Memory: Often defined as "memory without awareness” Also “Non-declarative” & “procedural” (Squire, Knowlton, & Mesen, 1993)

Implicit Memory Tasks Often defined as "memory without awareness” Perceptual Tasks Word identification Word stem completion Word fragment completion Degraded word naming Anagram solution Lexical decision Non-Verbal Tasks Picture fragment naming Object decision task Possible/impossible object decision Conceptual Tasks Word association Category instance generation Answering general knowledge questions

Implicit Memory Tasks Often defined as "memory without awareness” Perceptual Tasks Word identification Word stem completion Word fragment completion Degraded word naming Anagram solution Lexical decision Non-Verbal Tasks Picture fragment naming Object decision task Possible/impossible object decision Conceptual Tasks Word association Category instance generation Answering general knowledge questions

Implicit Memory Tasks Examples Study: bird, house, balloon, horse, rocket, dolphin (maybe levels of processing, or divided attention manipulation) Tests: Lexical decision – bronk ‘no’ - - horse ‘yes’ -- … Stem Completion - hor- “horde” vs “horse” Fragment Completion - h_r_s_ “hares” vs “horse” Category exemplar production - Animal-? “pig” vs “horse” Word Association - saddle - ? “leather” “bags” “horse”

Implicit Memory Tasks Examples Study: bird, house, balloon, horse, rocket, dolphin (maybe levels of processing, or divided attention manipulation) Tests: Picture fragment naming

Do amnesics have memory? Warrington and Weiskrantz (1968, 1970, 1974) showed differences in memory performance for amnesic patients Amnesic patients Can’t complete typical explicit memory tasks Typically don’t even remember seeing a list Performance on implicit tasks is similar to control participants Typically, don’t even remember seeing a list at all, let alone what words were on the list.

Explicit vs. Implicit Memory The Search for Dissociations Suggests that these tasks rely on different forms of memory Dissociation = different effects of an IV on the two test types (similar to the recognition vs. recall dissociations) Work since then has focused on looking for dissociations

Explicit vs. Implicit Memory Jacoby (1983): Generation Effect Study tasks Read aloud w/o context COLD Read w/ context hot – COLD Generate from context hot - ??? Test tasks Recognition Perceptual Identification Typically, don’t even remember seeing a list at all, let alone what words were on the list. Opposite pattern of results with implicit task

Explicit vs. Implicit Memory Roediger & Weldon, (1987) Study tasks Lists of pictures and words Test tasks Free recall of pictures and words Word fragment completion Priming effect: compared studied vs. unstudied completions Typically, don’t even remember seeing a list at all, let alone what words were on the list.

Explicit vs. Implicit Memory Rajarm, Srinivas, & Travers (2001) Attention Effect Study Full attention read word as quickly as possible Divided attention Name the color the word is presented in Test Word stem completion 2 instructions Use words from earlier list First word you think of Typically, don’t even remember seeing a list at all, let alone what words were on the list.

Explicit vs. Implicit Memory Tulving, Schacter, & Stark (1982): Forgetting Effects Study List of words Test Word fragment completion After 1 hr. & 7 days later Typically, don’t even remember seeing a list at all, let alone what words were on the list. Memory score = priming effect Compare fragment completions of old vs. new items

Mixing Measures Tasks are not “process pure” (Jacoby, 1991) Indirect measures of memory may be “contaminated” by intentional uses of memory E.g., in stem completion task, subjects might remember items from previous list and use them to complete the stems Direct measures may be influenced by unconscious or automatic influences (Jacoby, Toth, & Yonelinas, 1993) Process-Dissociation Procedure was developed to separate automatic (unconscious) and conscious processes Conscious vs. automatic memory?

Process Dissociation Procedure Jacoby (1991) Read a list of words – List 1 Hear a list of words – List 2 Two recognition tests: Both tests include List 1, List 2 and novel words. Inclusion = complete task with studied or any item Respond “old” if word was on either list. Exclusion = complete task with item NOT studied (exclude studied items) Respond “old” only if word was on List 2. Currently, most popular measurement method

Process Dissociation Procedure Jacoby (1991) Can calculate C and A for each condition in the experiment C = (Proportion of studied items in inclusion) - (Proportion of studied items in exclusion) A = (Proportion of studied items in exclusion) / (1-C) The C and A values are estimated as proportions - values between 0 and 1.0 Data Proportion of studied items in inclusion = C + (1-C)(A) Proportion of studied items in exclusion = (1-C)(A)

Process Dissociation Procedure Jacoby (1991) Exclusion: Respond “old” only if word was on List 2. Use equations to calculate conscious (C) and automatic (A) memory from target performance on the tasks P(old) = A(1-C) Subject will only respond “old” to List 1 words if two things happen: A: The automatic process responds “old” due to a feeling of familiarity (1-C): The intentional process fails to recognise the word (if it had, it would recall it was from List 1)

Process Dissociation Procedure Jacoby (1991) Inclusion: Respond “old” if word was on either list. Use equations to calculate conscious (C) and automatic (A) memory from target performance on the tasks P(old) = C + A (1-C) If either process concludes “old”, the subject will respond “old” A: Automatic process will also have a certain probability of concluding “old” for List 1 words C: Conscious (intentional) process will have a certain probability of concluding “old” for List 1 words

Process Dissociation Procedure Jacoby (1991) Read a list of words – List 1 Hear a list of words – List 2 Inclusion = Respond “old” if word was on either list. Exclusion = Respond “old” only if word was on List 2. Inclusion test P(old) = 0.48 Exclusion test P(old) = 0.37* C = Inclusion – Exclusion = 0.11 A = Exclusion / (1-C) = 0.37 / 0.89 = 0.42 *in exclusion condition, “OLD” are errors Currently, most popular measurement method

Process Dissociation Procedure Jacoby, Toth, & Yolelinas (1993): Attentional effects Study: read words full attention divided attention – read aloud while listening for odd numbers Task: stem completion: inclusion: complete with list word or guess green stem  inclusion (may use as a cue from list) exclusion: complete with new words only red stem  exclusion (complete with word not from list) Currently, most popular measurement method

Process Dissociation Procedure Jacoby, Toth, & Yolelinas (1993) (Exp 1b) Divided attention: Inclusion task:  P(old) Exclusion task:  P(old) Results: Inclusion: div (46%) < full (61%) Exclusion: div (46%) > full (36%) Interpretation: div attention knocked out recollection recollection  accuracy in both conditions Currently, most popular measurement method

Process Dissociation Procedure Jacoby, Toth, & Yolelinas (1993) (Exp 1b) Conclusions Conscious recollection greatly reduced under divided attention condition Conscious Automatic Full .25 .47 Divided .00 .46 Currently, most popular measurement method

Process Dissociation Procedure Toth, Reingold, and Jacoby (1994): Levels of Processing Study Pleasantness rating Shared vowels Test Stem completion task Conscious Automatic Deep .27 .42 Shallow .03 .45 Study Read word Say aloud missing word in sentence Test Stem completion task Typically, don’t even remember seeing a list at all, let alone what words were on the list. Conscious Automatic Read .21 .48 Generate .34 .28

Accounting for Implicit and Explicit Effects Four major approaches have been proposed The Activation view Multiple Memory systems view Transfer appropriate processing view Bias View Explicit contamination STOP HERE FOR TODAY

Activation view Insert slide here These are the systems criteria that people generally agree upon.

Memory Systems Many believe there are different systems of memory What is a system? Could involve different brain areas (amnesia) Could involve different rates of forgetting These are the systems criteria that people generally agree upon.

Memory Systems Squire (1987)

Memory Systems Squire (1987)

Memory Systems Brain areas Brain imaging studies found that different areas of the brain are used when completing implicit and explicit tasks But there isn’t just one structure involved in each type of memory And different kinds of implicit tasks seem to involve different areas Conclusion: brain area involvement may be a function of type of processing and type of memory Perceptual vs. conceptual tasks use different brain areas

Memory Systems Forgetting Tulving et al. (1989) showed a difference in forgetting rate for recognition and fragment completion Confirmed with other tasks (stem completion)

Memory Systems Forgetting But these studies looked at long-term forgetting (days, months) Didn’t follow RIC or use PDP

Memory Systems Forgetting More recent studies showed no difference in forgetting rates for implicit/explicit stem completion Used RIC and PDP

Memory Systems Typically, don’t even remember seeing a list at all, let alone what words were on the list.

Memory Systems Typically, don’t even remember seeing a list at all, let alone what words were on the list.

Mixing Implicit and Explicit Effects Jacoby (1990) proposed that implicit vs. explicit memory is confounded with two different kinds of memory processes (associated with two kinds of information) Memory system Mode of Processing Declarative (Episodic) Procedural (Priming) Perceptual (Data-driven) Perceptual identification Word Fragment Completion Meaning based (conceptually-driven) Free Recall Recognition Explicit contamination

Processing View Based on TAP view Tasks used for implicit memory usually have perceptual cues app- a_p_l_ Explicit tasks often are more conceptual (generation of items in free recall occurs through semantic relations between items)

Processing View Differences found between implicit/explicit tasks could reflect perceptual/conceptual differences Tested by Blaxton (1989)

Processing View Explicit Implicit Perceptual Task ???? Stem and fragment completion Conceptual Free recall Typically, don’t even remember seeing a list at all, let alone what words were on the list.

Processing View Explicit Implicit Perceptual Task Graphemic cued recall Stem and fragment completion Conceptual Free recall Gen. Knowledge Typically, don’t even remember seeing a list at all, let alone what words were on the list.

Processing View Read/Generate study Compared tasks across both dimensions

Typically, don’t even remember seeing a list at all, let alone what words were on the list.

Processing View Shows that match between study and test processing is more important Weldon & Roediger (1987) found different picture superiority effect for two implicit tasks

Summary of Implicit/Explicit TAP may be more important than memory process Implicit and explicit tasks are not “process pure” PDP offers a measurement method for processes Implicit/Explicit memory show dissociations on several variables

Explicit vs. Implicit memory Generation effect (Java, 1993) - found for explicit but reversed for implicit Subjects studied words - read or generated Completed implicit and explicit stem completion Read - horse Generate - A jockey rides a ____ in a race. Hor- complete with studied word vs. complete with first word you think of

Explicit vs. Implicit memory Level of Processing (Roediger et al., 1992) - found for explicit but not implicit Subjects studied words - pleasantness vs. letter tasks Completed implicit and explicit stem and fragment completion

Explicit vs. Implicit memory Attention (Mulligan, 1998) - dividing attention at study reduces explicit not implicit Study - just study words vs. study words and do extra task Test - implicit/explicit fragment completion

Explicit vs. Implicit memory Forgetting (Tulving, Schacter, & Stark, 1982) - difference in forgetting rates for explicit/implicit task performance Looked at performance for recognition and implicit fragment completion at 1 hr and 2 days Recognition performance declined, but implicit task performance did not

Processing View Studied pictures and words Tested with picture fragment naming and word fragment completion Picture fragment naming = name degraded picture with first thing it looks like

Processing View Typically, don’t even remember seeing a list at all, let alone what words were on the list.

Processing View Supports the perceptual/conceptual distinction But distinction not always shown Weldon and Coyote (1996) compared picture/word memory with category production tasks Found picture superiority for explicit category production, but no difference for implicit task

Stochastic Independence Hayman and Tulving (1989) Measure correlation between explicit and implicit task performance If not correlated (independent), then tasks measure different processes

Dual-process theories Dissociating Recollection and Familiarity Process Dissociation Procedure (Jacoby, 1991) Task: Participants study two sets of items in different contexts Two different recognition tests follow: Inclusion Condition: Say “yes” if they recognize an item from either context Correct recognition = Recollection + Familiarity Exclusion Condition: Say “yes” only if they recognize an item from one of the two contexts Familiarity = False alarms in exclusion condition Recollection = Inclusion’s correct recognition minus Familiarity Used to further investigate two possible processes involved in recognition Recognition - Old/New response + Remember/Know judgment for “Old” items Remember = consciously recollect details of the item’s presentation Know = sure an item was presented, but can’t recall any of the details of Presentation R/K responses for correct “Old” items have been shown to differ for the following effects: Typically studied pics are better remembered than words (picture superiority effect) R: Pics > words and K: words > pics Generate similar or related word Hot - ? Cat - ? vs. reading hot-cold and cat-dog