PSY 368 Human Memory Memory Implicit memory. Outline Theories accounting for Implicit vs. Explicit memory Experiment 2 Signal detection analysis Process-dissociation

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<ul><li><p>PSY 368 Human MemoryMemory Implicit memory</p></li><li><p>OutlineTheories accounting for Implicit vs. Explicit memoryExperiment 2 Signal detection analysisProcess-dissociation procedure, working through our example (probably not time, so after break)</p></li><li><p>Memory TasksTest InstructionsStudy InstructionsImplicit Memory: Often defined as "memory without awarenessAlso Non-declarative &amp; procedural (Squire, Knowlton, &amp; Mesen, 1993)</p><p>indirectdirectincidentalimplicit memoryexpts.Levels of Processingexpts.intentional?explicit memoryexpts.</p></li><li><p>Implicit/Explicit DissociationsMany demonstrations of different effects depending on whether implicit or explicit tasks are usedAmnesic patientsLevels of processing manipulationsPleasantness vs. vowel comparisonsGeneration effectDivided attentionPicture-word superiorityNote. Most of weve talked about concern repetition priming effect (study horse and respond horse)</p></li><li><p>Four major approaches have been proposedThe Activation viewMultiple Memory systems viewTransfer appropriate processing viewBias View</p><p>Accounting for Implicit/Explicit Dissociations</p></li><li><p>Four major approaches have been proposedThe Activation viewMultiple Memory systems viewTransfer appropriate processing viewBias View</p><p>Accounting for Implicit/Explicit Dissociations</p></li><li><p>The Activation ViewPriming on indirect tests is attributable to the temporary automatic activation of preexisting representations.Because it is automatic, it occurs without elaborative processing and thus has little to no contextual informationWeak Point Can not explain priming over long time periodsSome implicit priming over days or even weeks (e.g., Sloman, et al, 1988)Can not explain priming without pre-existing representationsThe least popular of the four views</p></li><li><p>Four major approaches have been proposedThe Activation viewMultiple Memory systems viewTransfer appropriate processing viewBias View</p><p>Accounting for Implicit/Explicit Dissociations</p></li><li><p>Multiple Memory SystemsMany dissociations between direct and indirect tests of memory arise because the tests tap different underlying memory systems.Squire (1987)</p></li><li><p>Multiple Memory SystemsMany dissociations between direct and indirect tests of memory arise because the tests tap different underlying memory systems.Tulving (1984)</p></li><li><p>Multiple Memory SystemsWhat is a system?It is NOT a processIt is NOT a task</p><p>Some different ways that systems have been defined</p><p>Schacter and Tulving (1994)</p></li><li><p>Multiple Memory SystemsWhat is a system?Functional DissociationsTask that taps into system A that has no effect (or a different effect) in System BDifferent neural substratesSystem A involves different brain areas than System B (brain damage cases and neural imaging studies)Stochastic independencePerformance on System A task uncorrelated with performance on a System B taskFunctional incompatibilityCould involve different rates of forgettingFunction carried out by System A can not be done by System BSchacter and Tulving (1994)</p></li><li><p>Multiple Memory SystemsWhat is a system?Schacter and Tulving (1994)</p><p>SystemOther NameSubsystemsCharacteristicsProceduralNondeclarativeMotor skillsNon-conscious operation(indirect)Cognitive skillsSimple conditioningSimple associative learningPerceptual representationNondeclarativeVisual word formAuditroy word formStructural descriptionPrimary memoryWorking memoryVisualConscious operation(direct)AuditorySemanticGenericSpatialFactualRelationalKnowledgeEpisodicPersonalAutobiographicalEvent memory</p></li><li><p>Brain areasBrain imaging studies found that different areas of the brain are used when completing implicit and explicit tasksNote: more than one structure involved in each type of memory</p><p>Buckner et al (1995) PET studyMultiple Memory Systems</p></li><li><p>Brain areasBrain imaging studies found that different areas of the brain are used when completing implicit and explicit tasks</p><p>Gabrieli et al (1995) Case study of MSMRI of MSs brainIntact performance on explicit tests of recognition and cued recallIntact performance on implicit test of conceptual memoryImpaired performance on implicit tests of visual perceptual memorySuggests a specific deficit in visual implicit memoryStudied lists of wordsPerceptual identification and recognition taskMultiple Memory Systems</p></li><li><p>Brain areasDifferent kinds of implicit tasks seem to involve different areasPerceptual vs. conceptual tasks appear to use different brain areas</p><p>Conclusion: brain area involvement may be a function of type of processing and type of memory</p><p>Buckner &amp; Koutstall (1998) fMRI studyMultiple Memory Systems</p></li><li><p>Stochastic IndependenceHayman and Tulving (1989)Measure correlation between explicit and implicit task performanceIf not correlated (independent), then tasks measure different processes Multiple Memory SystemsForgettingTulving et al. (1989) showed a difference in forgetting rate for recognition and fragment completionConfirmed with other tasks (stem completion)</p></li><li><p>StrengthsFits well with dissociations foundIn patientsIn experimentsMultiple Memory SystemsProblemHard to find consensus on what the systems areMay be too easy to posit a new system</p></li><li><p>Four major approaches have been proposedThe Activation viewMultiple Memory systems viewTransfer appropriate processing viewBias View</p><p>Accounting for Implicit/Explicit Dissociations</p></li><li><p>The key to good performance is similarity of processes involved in encoding vs. retrieval, be it implicit or explicit, perceptual or conceptual testImplicit and explicit may refer to different processes, yet the key to performance is matching processes.Processes at encodingProcesses at testOverlap determines retrieval successTransfer Appropriate ProcessA consequence: conceptual processing is the common core in free recall and implicit conceptual tasks, hence performance on these two types of task should be equal. </p></li><li><p>Transfer Appropriate ProcessAssumes:Performance depends of match between processing at study and processing at test.Analogous to encoding specificity. Two-types of Processes (Jacoby, 1990)Data-driven (perceptual) processing of physical features.Conceptually-driven (semantic) processing for meaning</p><p>Typically confounded, however, it is possible to un-confound test-type from process-type</p></li><li><p>Jacoby (1990) proposed that implicit vs. explicit memory is confounded with two different kinds of memory processes (associated with two kinds of information)Mixing Implicit and Explicit Effects</p><p>Memory system</p><p>Mode of ProcessingDeclarative(Episodic)Procedural(Priming)Perceptual(Data-driven)Perceptual identificationWord Fragment CompletionMeaning based(conceptually-driven)Free RecallRecognition</p></li><li><p>Data-driven (Perceptual):fragment completionstem completionanagram completionlexical decisionperceptual identification</p><p>Conceptually-driven(Semantic):word associationdoctor ??category-instance generationname a mammalgeneral knowledgeThe capital of the US is ?</p><p>Transfer Appropriate Process</p></li><li><p>Goal to demonstratedata-driven processing can affect direct testsdata-driven processing do not necessarily affect indirect testsBlaxton (1989)Transfer Appropriate Process</p><p>Data-drivenConceptually-drivenDirectGraphic-cuedRecallFree RecallIndirectFragmentCompletionGeneralKnowledge</p></li><li><p>Target word: bashfulgraphic-cued recall: looks like bushfulfree recallfrag completion: b_sh_u_General knowledge: Name one of the 7 dwarfs Blaxton (1989)Transfer Appropriate ProcessSs saw or heard lists of words (key IV here)</p><p>Data-drivenConceptually-drivenDirectGraphic-cuedRecallFree RecallIndirectFragmentCompletionGeneralKnowledge</p></li><li><p>PredictionsSystems view: modality match should affect only indirect tests (if indirect tap separate system, then modality should affect them in the same way) for both implicit tests: visual &gt; auditory for both explicit test: visual = auditoryBlaxton (1989)Transfer Appropriate ProcessSame pattern of results regardless of modalityVisual better than auditory for both </p><p>Data-drivenConceptually-drivenDirectGraphic-cuedRecallFree RecallIndirectFragmentCompletionGeneralKnowledge</p></li><li><p>PredictionsTAP View: modality match should affect data-driven tasks only. (priming depends on match between study/test processing match &amp; not on indirect vs direct): for both data-driven tests: visual &gt; auditory for both conceptually-driven tests: visual = auditory</p><p>Blaxton (1989)Transfer Appropriate ProcessVisual should be better than auditoryVisual and auditory should be about the same</p><p>Data-drivenConceptually-drivenDirectGraphic-cuedRecallFree RecallIndirectFragmentCompletionGeneralKnowledge</p></li><li><p>ResultsPriming Effect (V &gt; A) for data-driven tasks only:indirect: frag completiondirect: graphemic-cued recall</p><p>Not all indirect tests display priming effect.Gen Know (indirect, conceptual): V = ABlaxton (1989)Transfer Appropriate ProcessConclusionsSupport view that processing rather than system is what is important</p></li><li><p>Four major approaches have been proposedThe Activation viewMultiple Memory systems viewTransfer appropriate processing viewBias View</p><p>Accounting for Implicit/Explicit Dissociations</p></li><li><p>The Bias ViewProposed to account for repetition priming effects. Prior presentation of an item can bias subsequent processing of the item on later presentations (if you see it once, you are more likely to interpret in the same way later)Multiple systems attributes this to 3 separate systems, but doesnt really offer an explanationTAPs answer is considered circular (you respond faster the second time because of transfer appropriate processing, which was developed to account for priming effects)</p></li><li><p>The Bias ViewBias Views account for repetition priming effects. 1. First See one of old woman and young woman2. Second See ambiguous woman3. People are more likely to interpret the ambiguous picture as the same person as the unambiguous picture Bias entails both cost and benefitsCost : There will be an advantage if prior processing is appropriate for the current taskBenefits : There will be a disadvantage if prior processing is inappropriate for the current task</p><p>1. First SeeOld WomanYoung Woman2. Second SeeAmbiguous -&gt; Old WomanAmbiguous -&gt; Young Woman</p></li><li><p>Comparing the theoriesStrengthsProcessing perspectiveNo need for separate systems (true of Bias view too)Bias View may be seen as a complement to the TAP viewWeaknessesDoesnt explain impact of conscious awarenessTrouble with finer grain distinctions between tasksTAPMultiple Systmes</p><p>StrengthsGood fit for deficit data (but may be too easy to propose new systems)WeaknessesHas troubles with some data showing differential decline in memory performance with agingSometimes difficult to make specific predictions in advance</p></li><li><p>Implicit Memory SummaryImplicit memory is memory without awareness.Implicit and explicit tasks are not process purePDP offers a measurement method for processesImplicit memory is different memory from explicit memory by experimental dissociations.There is 4 main accounts for implicit memoryProbably a complex relationship between systems and processes</p></li><li><p>Experiment 2Recall that for experiment 2 you each collected data from three participants. IV levels Prediction: our instructions would lead participants to shift their criterion for what counts as old vs. new.Signal detection analysis</p></li><li><p>Signal Detection TheoryRecognition accuracy depends on:Whether a signal (noise/target memory) was actually presentedThe participants responseThus, there are four possible outcomes:</p><p>HitsCorrectly reporting the presence of the signalCorrect RejectionsCorrectly reporting the absence of the signal</p><p>False AlarmsIncorrectly reporting presence of the signal when it did not occurMissesFailing to report the presence of the signal when it occurredCORRECTINCORRECT</p></li><li><p>Signal Detection TheoryCalculating d and C (or )Discriminability (d):Step 1) Look up the z-score for the average Hit and False Alarm rates. Step 2) Apply the formula d = zHIT zFA, where zFA is the z-score for FAs and zHIT is the z-score for Hits.Criteria C (or ):Take the negative of the average of zHIT and zFA. This is the criterion value C. Remember that positive C values indicate a conservative response bias, while negative C values indicate a liberal response bias.http://memory.psych.mun.ca/models/dprime/</p></li><li><p>Experiment 2NeutralConservativeLiberalN=21 per conditionTotal possible hits or false alarms = 20AveragesProportions (avg/20)</p><p>TargetLureOldHit15.050.75False Alarm2.480.12</p><p>TargetLureOldHit12.050.60False Alarm1.140.06</p><p>TargetLureOldHit16.950.85False Alarm4.380.22</p></li><li><p>Experiment 2NeutralConservativeLiberald = 1.85C = 0.25d = 1.81C = 0.65d = 1.81C = -0.13http://memory.psych.mun.ca/models/dprime/</p><p>TargetLureOldHit15.050.75False Alarm2.480.12</p><p>TargetLureOldHit12.050.60False Alarm1.140.06</p><p>TargetLureOldHit16.950.85False Alarm4.380.22</p></li><li><p>Experiment 2NeutralConservativeLiberald = 1.85C = 0.25d = 1.81C = 0.65d = 1.81C = -0.13</p></li><li><p>Experiment 2NeutralConservativeLiberald = 1.85C = 0.25d = 1.81C = 0.65d = 1.81C = -0.13OldNew- Criterion + </p></li><li><p>Experiment 2Neutrald = 1.85C = 0.25OldNew- Criterion + </p></li><li><p>Experiment 2Conservatived = 1.81C = 0.65OldNew- Criterion + </p></li><li><p>Experiment 2Liberald = 1.81C = -0.13OldNew- Criterion + </p><p>****Explicit contamination*Explicit contamination*Explicit contamination*Perceptual vs. conceptual tasks use different brain areas*Perceptual vs. conceptual tasks use different brain areas*(A) Horizontal sections from two levels show fMRI activation maps for a shallow encoding task contrasted with fixation and for a deep encoding task contrasted with fixation (averaged data from 12 normal subjects; K-S statistical activation map threshold = P &lt; 0.001; brighter colors indicate greater significance; functional data overlie averaged anatomic image; right shown on the right). Both tasks share certain brain areas in common such as posterior visual areas whereas only the deep encoding task shows increased activation of left inferior and dorsal prefrontal areas (indicated with yellow arrows). These robust activations (P &lt; 108) are at peak coordinates [Talairach 1998 atlas (91) (x, y, z)] -40, 9, 34 and -46, 6, 28 for the more dorsal activations and -40, 19, 3 and -43, 19, 12 for the more ventral prefrontal activations. The direct contrast between the deep and shallow encoding tasks also indicated that these regions differed significantly. (B) A horizontal section showing left dorsal prefrontal cortex activation in an amnesic patient during a deep encoding task, collected in collaboration with Verfaellie, Schacter, and Gabrieli. Robust activation was detected at -46, 3, 31 similar to normal subjects. The time course of activation within this region is shown to the right. Repeating items across the deep encoding task revealed significantly reduced activation (priming) as indicated by the time course (+, fixation control condition). This latter finding suggests that priming-related changes are present at a functionalanatomic level in amnesia, consistent with preserved behavioral priming often observed in amnesia.***Explicit contamination*Perceptual implicit memory tasks: better if retrieval involves similar perceptual processes to the ones used in encoding.Conceptual tests: TAP predictions on conceptual implicit memory tests are identical to TAP predictio...</p></li></ul>