Memory and Memory and CognitionCognition

PSY 324PSY 324

Topic: Long-term Memory- Encoding Topic: Long-term Memory- Encoding and Retrievaland Retrieval

Dr. Ellen CampanaDr. Ellen Campana

Arizona State UniversityArizona State University

Storage of MemoriesStorage of Memories

Information is Information is usedused in one type of memory in one type of memory system (STM / WM) but in order for it to stick system (STM / WM) but in order for it to stick around for longer than a few seconds it needs around for longer than a few seconds it needs to be transferred into Long-term Memoryto be transferred into Long-term Memory Transferring information TO LTM is called Transferring information TO LTM is called

encodingencoding or or storagestorage Vocabulary note:Vocabulary note:

CodingCoding refers to the refers to the formform in which information is in which information is representedrepresented

EnEncoding coding refers to the refers to the processprocess used to get information used to get information into LTMinto LTM

Transferring information OUT OF LTM in order to Transferring information OUT OF LTM in order to use it in STM/WM is called use it in STM/WM is called retrievalretrieval

RehearsalRehearsal We saw last chapter that in certain cases simply We saw last chapter that in certain cases simply

repeating information can cause it to be storedrepeating information can cause it to be stored What affect showed this in the last class???What affect showed this in the last class???

Simply repeating information is called Simply repeating information is called maintenance rehearsalmaintenance rehearsal because it is most useful because it is most useful for keeping the information in STM/WMfor keeping the information in STM/WM Maintenance rehearsalMaintenance rehearsal is actually NOT an effective way is actually NOT an effective way

to transfer information to LTM to transfer information to LTM A more effective way to encode information is A more effective way to encode information is

through through elaborative rehearsalelaborative rehearsal – making – making connections between the new item and memories connections between the new item and memories you already haveyou already have Does this sound familiar? What concept is like this in STM?Does this sound familiar? What concept is like this in STM?

Levels of Processing TheoryLevels of Processing Theory explains these explains these differencesdifferences

Levels of Processing TheoryLevels of Processing Theory(Craik & Lockhart, 1972)(Craik & Lockhart, 1972)

Basic idea: memory depends on the specific Basic idea: memory depends on the specific process used to get information into LTMprocess used to get information into LTM Shallow processing:Shallow processing: little attention to meaning, little attention to meaning,

based on surface characteristicsbased on surface characteristics Count the vowelsCount the vowels

Deep processing:Deep processing: considering meaning and/or considering meaning and/or relating items to other information in LTMrelating items to other information in LTM

Think about how useful it would be on a desert islandThink about how useful it would be on a desert island Try the demo on page 198 (takes too long for Try the demo on page 198 (takes too long for

class)class) Confirmed in many different studies of Confirmed in many different studies of

memory for words, but two levels turned out memory for words, but two levels turned out to be too simpleto be too simple

Levels of ProcessingLevels of Processing

Craik & Tulving (1975) introduced Craik & Tulving (1975) introduced more levelsmore levels Shallow: A question about the physical Shallow: A question about the physical

featuresfeatures Is the word printed in capital letters? [bird]Is the word printed in capital letters? [bird]

Deeper: A question about rhymingDeeper: A question about rhyming Does the word rhyme with Does the word rhyme with traintrain? [pain]? [pain]

Deepest: A fill-in-the-blanks questionDeepest: A fill-in-the-blanks question Does the word fit in the sentence “he saw a Does the word fit in the sentence “he saw a

___ on the street”? [car]___ on the street”? [car]

Levels of ProcessingLevels of Processing

% of words recalled

after delay

Fill-in-the-

blanks

Rhyme Capital Letters

Levels of ProcessingLevels of Processing Are you convinced?Are you convinced?

People were, at first. But then a bunch of new People were, at first. But then a bunch of new tasks were tried and a people discovered a tasks were tried and a people discovered a circularitycircularity in the argument in the argument What makes a level “deep”? It leads to better What makes a level “deep”? It leads to better

memory.memory. And why care about “depth”? It can predict memory.And why care about “depth”? It can predict memory.

Dissatisfaction with the Levels of Dissatisfaction with the Levels of Processing Theory coincided with Processing Theory coincided with introduction of a new theory about the introduction of a new theory about the encoding of long-term memory: encoding of long-term memory: Transfer-Transfer-Appropriate ProcessingAppropriate Processing

Transfer-Appropriate Transfer-Appropriate ProcessingProcessing

Basic idea: memory is best when the Basic idea: memory is best when the task at task at encodingencoding matches the task at matches the task at retrievalretrieval Morris and Coworkers (1977) Morris and Coworkers (1977)

independently varied the tasks at encoding independently varied the tasks at encoding and retrievaland retrieval

Encoding tasks: Encoding tasks: meaning-taskmeaning-task (fill-in-the- (fill-in-the-blanks) and blanks) and rhyming-taskrhyming-task

Retreival tasks: Retreival tasks: standard recognition taskstandard recognition task and and rhymed recognition task rhymed recognition task (does it rhyme with a (does it rhyme with a word you heard?)word you heard?)

Transfer-Appropriate Transfer-Appropriate ProcessingProcessing

Fill-in-the-

blanks

Rhyme

% correct

Standard Recognition

TestRhymed

Recognition Test

Matching

Other factors that aid Other factors that aid encodingencoding

NOTE: All of these are about encoding, NOTE: All of these are about encoding, but caused by increasing but caused by increasing retrieval cuesretrieval cues

Forming connections with other Forming connections with other informationinformation More vivid /detailed => better memoryMore vivid /detailed => better memory Visually imagining pairs of words => better Visually imagining pairs of words => better

memorymemory Bower & Wizenz (1970)Bower & Wizenz (1970)

Self-reference effectSelf-reference effect Rogers and Coworkers (1979)Rogers and Coworkers (1979)

Other factors that aid Other factors that aid encodingencoding

Generating informationGenerating information The generation effect (Slameka and Graf, The generation effect (Slameka and Graf,

1978)1978) Read (king-crown) vs fill-ins (king-cr_____)Read (king-crown) vs fill-ins (king-cr_____) Memory for words that were filled in is betterMemory for words that were filled in is better

Organizing informationOrganizing information Bower and colleagues –similar groupingsBower and colleagues –similar groupings Bransford and Johnson – balloon picture Bransford and Johnson – balloon picture

studystudy

Encoding SpecificityEncoding Specificity

Basic idea: Basic idea: Context of learning Context of learning (location, etc.)(location, etc.) can act as a retrieval cue can act as a retrieval cue It’s actually good for you that we’re using It’s actually good for you that we’re using

scan-tron!scan-tron! Diver Study (who?)Diver Study (who?)

Group of diversGroup of divers ½ learned a list on land½ learned a list on land ½ learned a list under water½ learned a list under water ½ tested on land½ tested on land ½ tested under water½ tested under water

State-Dependent State-Dependent LearningLearning

Basic idea: Basic idea: Your own internal stateYour own internal state can act as a retrieval cuecan act as a retrieval cue Emotions, sleep-deprivation state, Emotions, sleep-deprivation state,

chemicalschemicals

How Long-term How Long-term Memories are Memories are

StoredStored(biologically-speaking)(biologically-speaking)

Storage at the SynapseStorage at the Synapse

Remember Chapter 2, discussion of faces?Remember Chapter 2, discussion of faces?

Storage at the SynapseStorage at the Synapse Representation of each face is a memory Representation of each face is a memory

How did these particular memories come to How did these particular memories come to be represented by these particular neurons be represented by these particular neurons firing in this pattern?firing in this pattern?

Key is in the synapses between neuronsKey is in the synapses between neurons Neurotransmitters cause structural changesNeurotransmitters cause structural changes Structural changes modify the firing rate of Structural changes modify the firing rate of

neuronsneurons Hebbian LearningHebbian Learning, , Long-term Long-term

PotentiationPotentiation ““Neurons that fire together, wire together”Neurons that fire together, wire together”

Structure of a NeuronStructure of a Neuron

Storage at the SynapseStorage at the Synapse

Storage at the SynapseStorage at the Synapse Process of Process of Long-term PotentiationLong-term Potentiation

A and B are connected such that A’s axon A and B are connected such that A’s axon synapses with B’s dendritesynapses with B’s dendrite

Both A and B may be connected to many other neuronsBoth A and B may be connected to many other neurons When A and B fire at the same time, When A and B fire at the same time,

neurotransmitters cause structural changesneurotransmitters cause structural changes Effect is that over time the same stimulus will Effect is that over time the same stimulus will

produce faster firing rates by Bproduce faster firing rates by B Hebb came up with this in 1948, but Hebb came up with this in 1948, but

neurological evidence came much laterneurological evidence came much later Important because it is used in connectionist Important because it is used in connectionist

modelsmodels

Fragility of New Fragility of New MemoriesMemories

Much evidence that new memories are Much evidence that new memories are fragilefragile Concussions – memory for events just prior is lostConcussions – memory for events just prior is lost Electroconvulsive TherapyElectroconvulsive Therapy – again, memory for – again, memory for

events just prior is lost (at least temporarily)events just prior is lost (at least temporarily) Another dimension of amnesia Another dimension of amnesia

Retrograde amnesiaRetrograde amnesia – loss of declarative – loss of declarative memory for events prior to a traumamemory for events prior to a trauma Graded amnesiaGraded amnesia – loss worse for more recent – loss worse for more recent

memoriesmemories Anterograde amnesiaAnterograde amnesia – inability to form new – inability to form new

memoriesmemories

Graded AmnesiaGraded Amnesia H.M. in your book (had H.M. in your book (had hippocampushippocampus removed) removed)

Had both retrograde and anterograde amnesiaHad both retrograde and anterograde amnesia His His retrograde amnesiaretrograde amnesia was was gradedgraded

Could remember events before 10-15yrs before operationCould remember events before 10-15yrs before operation More recent memories, more damageMore recent memories, more damage

PAST FUTURE

Old memories have graded

damage

Operation New memories are never even formed

Graded AmnesiaGraded Amnesia Why talk about graded amnesia right now?Why talk about graded amnesia right now?

Demonstrates that Demonstrates that recent memories are more recent memories are more fragilefragile Some process must make memories less fragileSome process must make memories less fragile

Hippocampus involved in recent (not old) Hippocampus involved in recent (not old) memoriesmemories That’s because H.M. had no hippocampusThat’s because H.M. had no hippocampus

ConsolidationConsolidation is the process that makes is the process that makes memories less fragile over timememories less fragile over time Synaptic consolidationSynaptic consolidation Systems consolidationSystems consolidation

Process of ConsolidationProcess of Consolidation Synaptic consolidationSynaptic consolidation

First type to be studiedFirst type to be studied Rapid, happens over the time span of minutesRapid, happens over the time span of minutes Long-term PotentiationLong-term Potentiation is an example is an example

Systems consolidationSystems consolidation Large-scale reorganization of circuits of Large-scale reorganization of circuits of

neurons neurons Gradual, happens over days, weeks, months, Gradual, happens over days, weeks, months,

yearsyears Standard model of consolidationStandard model of consolidation

Retrieval depends on hippocampus during Retrieval depends on hippocampus during consolidationconsolidation

Afterwards, hippocampus no longer involved Afterwards, hippocampus no longer involved

Standard Model of Standard Model of ConsolidationConsolidation

Early on, memory is distributed across Early on, memory is distributed across the brain, no connections between active the brain, no connections between active cortical areascortical areas Sights, sounds, smells, etc. Sights, sounds, smells, etc.

Hippocampus coordinates activity across Hippocampus coordinates activity across the cortical area during memory the cortical area during memory reactivationreactivation Links form between active cortical areasLinks form between active cortical areas

Gradually the hippocampus is no longer Gradually the hippocampus is no longer involved in retrievalinvolved in retrieval

Standard Model of Standard Model of ConsolidationConsolidation

Standard Model of Standard Model of ConsolidationConsolidation

Much of consolidation (including Much of consolidation (including reactivationreactivation) happens during ) happens during sleepsleep / / relaxed wakefulnessrelaxed wakefulness

Can also happen duringCan also happen during rehearsal rehearsal Especially Especially elaborative rehearsalelaborative rehearsal

Results in situation where only cortical Results in situation where only cortical activity is necessary for activity is necessary for remote remote memoriesmemories Remote memories are memories for events Remote memories are memories for events

that occurred long agothat occurred long ago

Consolidation Consolidation ControversyControversy

That’s the nice clean model… but there is That’s the nice clean model… but there is controversy about the claim that the controversy about the claim that the hippocampus completely drops out of hippocampus completely drops out of retrievalretrieval Evidence for Evidence for no hippocampal involvementno hippocampal involvement

Brain imaging – Brain imaging – Medial Temporal LobeMedial Temporal Lobe (which (which contains the hippocampus) is not active for remote contains the hippocampus) is not active for remote memoriesmemories

Used Used semanticsemantic, not episodic, memories, not episodic, memories Evidence for hippocampal involvementEvidence for hippocampal involvement

Brain imaging studies looking at Brain imaging studies looking at episodicepisodic memories memories

Test RemindersTest Reminders

Studying for TestsStudying for Tests

Elaborate and Generate – why?Elaborate and Generate – why? Organize – why?Organize – why? Associate – why?Associate – why? Take breaks – why?Take breaks – why?

Distributed vs. Massed Practice EffectDistributed vs. Massed Practice Effect Match Learning and Testing Match Learning and Testing

ConditionsConditions …….or at least move around a lot.or at least move around a lot

The EndThe End