Presentation on theme: "Long-Term Memory: Encoding and Retrieval"— Presentation transcript:
1Long-Term Memory: Encoding and Retrieval Chapter 7Long-Term Memory: Encoding and Retrieval
2Some Questions to Consider What is the best way to store information in long-term memory?What are some techniques to help us get information out of LTM when we need it?How can the results of memory research be used to create more effective study techniques?How is it possible that a lifetime of experiences and accumulated knowledge can be stored in neurons?
3Storing Information in LTM Encoding: acquiring information and transforming it into memoryMaintenance rehearsalMaintains information but does not transfer it to LTMElaborative rehearsalTransfers information to LTM
4Levels of Processing Theory Memory depends on how information is encodedDepth of processingShallow processing: little attention to meaning (poor memory)Deep processing: close attention to meaning (good memory)
5Caption: (a) Sequence of events in Craik and Tulving’s (1975) experiment. (b) Results of this experiment. Deeper processing (fill-in-the-blanks question) is associated with better memory.
6Beware of Circular Reasoning! Which task causes deeper processing?Using a word in a sentenceDeciding how useful an object might be on a desert islandCan empirically measure the memory trace in each conditionConclude that stronger memory trace must have been caused by deeper processingBut depth of processing has not been defined independently of memory performanceTherefore, this is circular reasoning
7Caption: The circularity of defining depth of processing in terms of memory and then predicting that deeper processing will result in better memory.
8Other Factors that Aid Encoding ImageryCreating connections, cues for rememberingSelf-reference effectGeneration effectOrganizing to-be-remembered informationTesting
9Organization, Comprehension, and Memory Bransford & Johnson (1972)Presented participants with difficult-to-comprehend informationExperimental Group 1 first saw a picture that helped explain the informationExperimental Group 2 saw the picture after reading the passageControl Group did not see the pictureGroup 1 outperformed the others.Having a mental framework of comprehension aided memory encoding and retrieval
10Caption: Picture used by Bransford and Johnson (1972) to illustrate the effect of organization on memory.
11Which results in a stronger memory trace? Testing EffectWhich results in a stronger memory trace?Re-reading the materialBeing tested on the materialRoediger and Karpicke (2006) had participants read a passage and then eitherRecall as much as they couldReread the passageTested recall after a delay
12Caption: Results of the Roediger and Karpicke (2006) experiment Caption: Results of the Roediger and Karpicke (2006) experiment. Note that at longer times after learning, the performance of the testing group is better than the performance of the rereading group.
13Retrieving Information from LTM Retrieval: process of transferring information from LTM back into working memory (consciousness)Most of our failures of memory are failures to retrieve
14Retrieving Information from LTM Cued-recall: cue presented to aid recallIncreased performance over free-recallRetrieval cues most effective when created by the person who uses them
15We learn information together with its context Encoding SpecificityWe learn information together with its contextBaddeley’s (1975) “diving experiment”Best recall occurred when encoding and retrieval occurred in the same location
16Caption: (a) Design for Godden and Baddeley’s (1975) “diving” experiment. (b) Results for each test condition are indicated by the bar directly under that condition. Asterisks indicate situations in which study and test conditions matched.
17Caption: (a) Design for Grant et al. ’s (1998) “studying” experiment Caption: (a) Design for Grant et al.’s (1998) “studying” experiment. (b) Results of the experiment. Asterisks indicate situations in which study and test conditions matched.
18State-Dependent Learning Learning is associated with a particular internal stateBetter memory if person’s mood at encoding matches mood during retrieval
19Caption: (a) Design for Eich and Metcalfe’s (1989) “mood” experiment Caption: (a) Design for Eich and Metcalfe’s (1989) “mood” experiment. (b) Results of the experiment.
20Improving Learning and Memory ElaborateHighlighting is not enough!Generate and testOrganizeHelps reduce load on memoryMatch learning and testing conditions
21Improving Learning and Memory Associate what you are learning to what you already knowAvoid the “illusion of learning”Familiarity does not mean comprehensionTake breaksMemory is better for multiple short study sessionsConsolidation
22Improving Learning and Memory Distributed versus massed practice effectDifficult to maintain close attention throughout a long study sessionStudying after a break gives feedback about what you already know
23Information Storage at the Synapse Hebb (1948)Learning and memory represented in the brain by physiological changes at the synapseNeural record of experience
24Information Storage at the Synapse Long-term potentiation (LTP)Enhanced firing of neurons after repeated stimulationStructural changes and enhanced responding
25Caption: What happens at a synapse as (a) a stimulus is first presented. The record next to the electrode indicates the rate of firing in the axon of neuron B. (b) As the stimulus is repeated structural changes are beginning to occur. (c) After many repetitions, more complex connections have developed between the two neurons, which causes an increase in the firing rate, even though the stimulus is the same on that was presented in (a).
26Where Does Memory Occur in the Brain? Medial temporal lobeHippocampusPerirhinal cortex
27Caption: (a) Side view of the brain and (b) underside of the brain, showing the amygdala and structures in the medial temporal lobe (perirhinal cortex, parahippocampal cortex, entorhinal cortex, and hippocampus).
28The Fragility of New Memories Retrograde amnesia: loss of memory for events prior to the traumaAnterograde amnesia: cannot form new memoriesMemory for recent events is more fragile than for remote events
29Transforms new memories from fragile state to more permanent state ConsolidationTransforms new memories from fragile state to more permanent stateSynaptic consolidation occurs at synapses, happens rapidlySystems consolidation involves gradual reorganization of circuits in brain
30Standard model of consolidation Retrieval depends on hippocampus during consolidation; after consolidation hippocampus is no longer neededReactivation: hippocampus replays neural activity associated with memoryControversial
31Caption: (a) According to the standard model of consolidation, retrieval of recent memories depends on the hippocampus; cortical connections have not yet formed. Thus, for retrieval of recent memories, hippocampal activation is high and cortical activation is low. (b) Once consolidation has occurred, cortical connections have formed, and the hippocampus is no longer needed. Thus, for retrieval of remote memories, cortical activation is high, and there is no hippocampal activation.
32Multiple trace hypothesis ConsolidationMultiple trace hypothesisQuestions the assumption that the hippocampus is important only at the beginning of consolidationthe hippocampus has been shown to be activated during retrieval of both recent and remote memories (Gilboa et al., 2004)
33Are Memories Ever “Permanent”? Reactivation and reconsolidation evidence from research on animalsOccurs under certain conditionsHuman memory is a “work in progress”