PSY 323: Cognition

Chapter 7: Long-Term Memory: Encoding, Retrieval, & Consolidation

Encoding

•Mental Rehearsal ▫Maintenance Rehearsal

Repeating things over and over Helps maintain information in STM/WM

▫Elaborate Rehearsal Involves thinking about how new material

relates to information already stored in memory

Effective at transferring information into LTM

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Levels of Processing (LOP)

•Craik & Lockhart (1972); Nairne (2010)▫Quality of memory depends on how

information is encodedSee demo on next two slides

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For about 5 seconds per item, count # of vowels in each word

•Chair•Mathematics•Elephant•Lamp•Car•Elevator•Thoughtful•Cactus

Count backward from 100 by 3’s; when you get to 76, write down as many words as you can remember. Do that now.

Replication of Craik & Lockhart (1972)

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For about 5 seconds per item, visualize how useful the item would be on a deserted island

•Umbrella•Exercise•Forgiveness•Rock•Hamburger•Sunlight•Coffee•Bottle

Count backward from 99 by 3’s; when you get to 75, write down as many words as you can remember. Do that now.

Replication of Craik & Lockhart (1972); Nairne, Pandeirada, & Thompson 2007, 2008)

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How did you do?

•Chair•Mathematics•Elephant•Lamp•Car•Elevator•Cactus•Thoughtful

• Umbrella• Exercise• Forgiveness• Rock• Hamburger• Sunlight• Bottle• Coffee

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What Levels of Processing tells us…

Memory for words is better when they are linked to other knowledge•Depth of Processing seems to matter

Shallow Processing•Little attention to meaningDeep Processing•Close attention to meaning

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Experimental Evidence for LOP

Craik & Tulving (1975)

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Types of questions

Procedure•Shallow:

▫Is the word printed in capital letters?•Deeper:

▫Does the word rhyme with train?•Deepest:

▫Does the word fit into the sentence “He saw a ____ on the street?”

Craik & Tulving (1975)

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Levels of Processing

Deep processing takes longer but results in better memory.

Shallow

Deeper

Deepest

Craik & Tulving (1975)

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Aiding Encoding: Forming additional connections

Complex or descriptive sentences aid memory

•Chicken▫She cooked the chicken.▫The great bird swooped down and carried off

the struggling chicken.

•Which sentence would help you to remember the word “chicken?”

Forming Visual Images

Bower & Winzenz (1970)Procedure•Paired associate learning paradigm•15 noun pairs; 5 seconds to remember

▫ Group 1: Silently repeat▫ Group 2: Mental image

•After delay, participants are given first word and asked to remember the secondResults•Group 2 did better; recalled more than twice as many words

See next slide

Forming Visual Images

Interpretation•Illustrates the advantage of visual coding

Bower & Winzenz (1970)

Results

Linking Words to YourselfRogers et al. (1977)Experiment 1Procedure•Participants read a question for three seconds and then saw a word•They answered yes if the word was in the question and no if it wasn’t

Four types of questions:•Physical characteristics of word•Rhyming•Meaning•Self-reference

Linking Words to Yourself

Rogers et al. (1977)

Exp. 1: Results

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Linking Words to Yourself

Experiment 2

Rogers et al. (1977)

Results

Why are we more likely to remember words they connect to ourselves?Rogers et al. (1977)Experiments 1 & 2

Interpretation•One possible explanation is that the words become linked to something the participants in these experiments know well—themselves

The Generation EffectSlameka & Graf (1978)Procedure•Paired associate learning paradigm•Participants studied related word pairs

▫ Group 1: Read group▫ Group 2: Generate group

•After delay, participants asked to recall second word in pair after being presented with first wordResults•Group 2 did significantly betterInterpretation•Generating material yourself, rather than passively receiving it, enhances learning and retention

How do we recall or retrieve information that is not presently in conscious awareness?•Retrieval Cues

▫Stimuli that help us to get information stored in LTM

▫Seems to help the best if it taps into information that was encoded at the time of learning

Retrieval PracticeTesting Effect

Roediger & Karpicke (2006)Procedure•Participants read prose passages for 7 minutes followed by a 2-minute break during which they solved math problems.

▫Group 1: Testing group▫Group 2: Rereading group

•After various delays, all participants were given recall test

Retrieval PracticeTesting Effect

Roediger & Karpicke (2006)

Results

Interpretation•Retrieval can get better with practice (after extended delays)

Cued Recall

High school students listened to lists of 12, 24, and 48 words

Procedure & Results of Tulving & Pearlstone (1966)

Matching Conditions of Encoding & RetrievalEncoding Specificity Principle

Godden & Baddeley (1975)

Procedure•Participants randomly assigned to 4 groups:

Listen/RecallGroup 1: water/landGroup 2: land/waterGroup 3: water/waterGroup 4: land/land

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Matching Conditions of Encoding & Retrieval

Procedure & Results of Gooden & Baddeley (1975)

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Matching Conditions of Encoding & Retrieval

Procedure & Results of Grant et al. (1998)

Matching Conditions of Encoding & RetrievalInterpretation of both studies:• The effect of context is significant• Recall is better if the retrieval context is

similar to the encoding context

Gooden & Baddeley (1975); Grant et al. (1998)

State Dependent Memory

Moods Cue•Memory is better when a person’s internal state during retrieval matches their internal state during encoding•Information learned in a particular emotional state (e.g., depressed, happy, somber) may be more easily recalled when in that same state of mind

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State Dependent Memory

Procedure & Results of Eich & Metcalfe (1989)

State Dependent Memory

InterpretationThe effect of context is significant• Recall is better if the retrieval context is

similar to the encoding context

Transfer Appropriate Processing This phenomenon shows that memory performance is enhanced if the type of task at encoding matches the type of task at retrieval

Morris et al. (1977)Procedure•The encoding part of the experiment had two conditions:

▫The meaning condition ▫The rhyming condition

•Participants in both conditions heard a sentence with one word replaced by the word “blank”; 2 seconds later, they heard a target word

Transfer Appropriate Processing ProcedureMeaning Group•Answer “yes” or “no” based on the meaning of the sentence created by replacing “blank” with the target wordRhyme Group•Answer “yes” or “no” based on the rhyme created by replacing “blank” with the target word

Morris et al. (1977)

Transfer Appropriate Processing

Morris et al. (1977)

Results

Interpretation•This result would not be predicted by levels of- processing theory, but is predicted by the principle that better retrieval occurs if the encoding and retrieval tasks are matched

The Process of Consolidation…

Transforming new memories from fragile state (easily lost) to a permanent state (not easily lost)•Standard Model of Consolidation•Multiple Trace Hypothesis

Standard Model of ConsolidationThis model posits that the hippocampus important at first; not so much laterReactivation •A process in which the hippocampus replays the neural activity associated with memory•This activity results in the formation of connections between the cortical areas •This reactivation process occurs during sleep or during periods of relaxed wakefulness, and can also be enhanced by conscious rehearsing of a memory

Standard Model of ConsolidationReactivation •Eventually, the cortical connections become strong enough so that the different sites in the cortex become directly linked, and the hippocampus is no longer necessary •Thus, according to the standard model of consolidation, the hippocampus is strongly active when memories are first formed but become less active as memories are consolidated, until eventually only cortical activity is necessary to retrieve remote memories

Standard Model of ConsolidationEvidence for this model comes from occurrences of graded amnesia •Retrograde amnesia is most severe for events that occurred just before an injury

Retrograde amnesia•Loss of memory for events that have happened prior to trauma or disease

Standard Model of ConsolidationGradual decrease in amnesia for past events supports idea that connections between hippocampus and the cortical connections are formed and strengthened as time passes after an event and then vanish•Hippocampus is strongly active when memories are initially formed and recalled •Then becomes less involved as memories are consolidated •Eventually, the connections between the cortical areas themselves are enough to access remote memories

The Process of Consolidation…

Multiple Trace Hypothesis (MTH)•Hippocampus’ influence is important during latter stages of memory formation as wellGilboa et al. (2004)•Participants shown photographs of themselves engaging in various activities at times ranging from very recently to when they were 5 years old •The results of this experiment showed that the hippocampus was activated during retrieval of both recent and remote memories

Reconsolidation

•This theory posits that when a memory is retrieved, it returns to the STM state

•If undisturbed it will undergo consolidation again back into LTM

•However, it may not go undisturbed and is susceptible to alteration at this time

•Since reactivated memory is in a labile state, it can be blocked (just as in consolidation)

Credits

Some of the slides in this presentation prepared with the assistance of the following web sites: www.radford.edu/dhall/Matlin%20powerpoint

s/ch05%20edited.ppt archlab.gmu.edu/people/jthompsz/6-LongTermMemory_2.ppt