1 MEMORY UNIT Amnesias: some people are unable to explicitly remember any new information they learn. When introduced to someone they met a few minutes.

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MEMORY UNIT

Amnesias: some people are unable to explicitly remember any new information they learn. When introduced to someone they met a few minutes ago, they cannot remember ever having met this person. However, they can still learn to do some types of new tasks.

Different ways of thinking about new information has a large effect on what we remember. Why? What might help us to remember better? What causes us to forget?

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Three important points about memory(of many that could be chosen)

(1) Memory is not the same as recollection.Memory is critical for much that we do.There are different types of memories that may be affected by different manipulations, traumas, etc.

(2) Active, elaborative processing of information is important for ensuring good retention of the information.

(3) The context match between when we learn something and when we remember it has a large influence on how well we remember.

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MEMORY UNITA brief glimpse …………………..

Structure - a traditional view (for 50 minutes)

* Short Term Sensory Store (STSS) ** Iconic & Echoic

* Short-term Memory (STM) or Working Memory (WM)

* Long Term Memory (LTM) ** Declarative & Procedural ** Amnesias

Process

* Encoding * Storage - capacity & forgetting * Retrieval - strategies & codes

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Working Memory (short-term memory)

Storage (Capacity & Duration) * Capacity - memory span is 7 + 2 items (with recall immediately after presentation) But …. What’s an item? Chunk - a meaningful unit of information e.g. 2 1 7 2 4 4 1 0 9 5 or (217) 244-1095

* Duration - See letters then (to prevent rehearsal) count backwards from 299 by 7s ** 50% recall in 15 second

Encoding * Conrad effect - present letters to be memorized on a screen ** Recall errors are acoustic rather than visual (Present E - erroneously recall D not F) (but can be visual or semantic at times)

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Long Term Memory (LTM)

Storage (Capacity & Duration) * Capacity & Duration - for practical purposes, unlimited

Then why is forgetting observed?

• Interference rather than decay (primarily)• Memories are “there”• Retrieval difficulties

• Evidence against decay - less forgetting when asleep

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Forms of Interference:Retroactive Interference -- effect of learning later material

Original InterpolatedGroup Learning Learning TestExperimental List A List B List AControl List A Rest List A

Proactive Interference -- effect of having learned earlier material

PriorGroup Learning Learning TestExperimental List B List A List AControl None List A List A

To reduce interference: Use material from different semantic categories for different lists

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Encoding How do you get information into LTM?

(a) Maintenance (rote) rehearsal - emphasize phonological aspects of material

* Good for WM poor for LTM

(b) Elaborative rehearsal - emphasize semantic association * Good transfer to LTM -- example In what form is information encoded into LTM? * Primarily Semantic (though can store other forms)** Thirty seconds after hearing or reading two brief narratives they can not distinguish them if they had the same meaning

* Mnemonic strategies: Method of Loci, Rhyming … --good for remembering arbitrary information

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Elaborative processing is critical

The time spent memorizing and the intention to remember influence retention only if you actively process and elaborate the material

Construct an integrated representation of the new material (so it makes sense) and connect it to what you already know

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Retrieval from LTM - importance of context

Very common occurrence Environmental context

Learn underwater or on land. Test underwater or on land. Performance 50% better when match

State-dependence - internal context Better memory when match of states (even find some with mood)

Why? Indication of relevance

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Prior knowledge importance in retrieving from LTM

Try to remember your last physical exam See that some of what you remember is

based on your knowledge of physicals and some on the actual events from that physical

Also depends on match of prior knowledge you used in encoding and retrieving -- often have schemas (or organized knowledge) for encoding and retrieving routine events, etc.

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Some practices for good learning

Chunk information -- active processing into chunks allows for easier recall later

Be an active learner -- elaborate, summarize, relate information to what you already know, organize the information

Vary study and try to make it like the time when you may need to retrieve information -- space study, vary context, reinstate learning (mentally), practice retrieving information

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Differentiating WM from LTM (& among varieties of LTM)

Serial position (recall) curves

* Best recall at beginning (LTM) & end (WM) of list

Recency effect - diminished when another task is performed after the word list has been presented. Primacy effect is unaffected.

Primacy effect - diminished with fast presentation, low frequency words, unrelated words. Recency effect is unaffected.

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Probability of report

With delay between study and test, recency part of curvedecreases much more than primacy or middle.

Serial position1 2 3 4 5 6 7 8

Primacy RecencyWithout delay

With delay

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Clinical/Neuroanatomical Evidence

Bilateral lesions of the hippocampus ** Pre-surgical WM and LTM are ok ** Post-surgical

WM is ok Failure to develop (some) new LTMs

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Types of Memory and Amnesia Declarative memory - “knowing that…”

Examples “I am in medical school” My sister called last night.

Can be learned relatively quickly Flexible

Procedural memory -”knowing how” Examples

How to drive a car, speak English, tie a shoelace Learned relatively slowly Not flexible (used in specific ways)

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Amnesia

Retrograde --declarative memory loss of prior events Have trouble remembering from BEFORE brain

damage Most likely to recover oldest memories Most likely to lose ones nearer trauma Does not affect procedural memory (“Long kiss goodnight” -- many movies though rare)

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Amnesia

Anterograde -- cannot form new declarative memories Short-term memory is fine Does not affect procedural memory -- can even learn some new

skills (“Memento”)

Often see confabulations to cover memory loss -- clue

Several causes -- common one is thiamine deficiency (long-term alcohol abuse -- Korsakoff’s syndrome)

H.M.’s performance on mirror drawing

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Three important points about memory(of many that could be chosen)

(1) Memory is not the same as recollection. Memory is critical for much that we do.

There are different types of memories that may be affected by different manipulations, traumas, etc.

(2) Active, elaborative processing of information is important for ensuring good retention of the information.

(3) The context match between when we learn something and when we remember it has a large influence on how well we remember.

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Readings and Key TermsBernstein et al. - Chapter 7, 224-250

Iconic store chunk Interference: retroactive, proactive Rehearsal: maintenance, elaborative Context effects Serial position curve: primacy, recency Declarative and procedural memory Retrograde and anterograde amnesia