PSY 452 long term structures

Conceptual difference between STM and LTM

• STM: active contents of mind whereas

• LTM: sensory memory goes into active contents of mind and then are shelved; and then retrieved

Serial position effect

• tendency to best remember the first and las items in a series while forgetting the items in the middle

Primacy effect

• better remember information they encounter first in a sequence compared to information that comes later

• primacy items more likely to get into LTM due to greater amount of rehearsal

Recency effect

• phenomenon where people best remember to the most recent presented information

Serial position curve

• U shaped graph showing that people remember items at the beginning and end of a list better than items in the middle

Two-store view of SP effect

• shows that there are separation operation of STM and LTM

• showing that different parts of a list are retrieved from different memory stores

STM/LTM explanation of serial position effects

• earlier items get more rehearsal, got to LTM

• later items still in STM got dumped out

Glanzer and Cunitz (1966)

Experimental dissociation

• used to see how primacy and recency work on different operations of memory

• primacy remains and recency eliminated

Henry Molaison (H.M)

• Intact STM

• Intact LTM from before the operation

• Severe deficits in committing new information to LTM

Clive Wearing

• Severe damage to hippocampus

• Intact STM

• Intact LTM from long ago

• Severe deficits in committing new information to LTM

Jimmie G.

• Damage to hippocampus

• Intact STM

• Intact LTM from childhood and war service

• Severe deficits in committing new information to LTM

Patient K.F

• parietal lobe damage

• STM capacity of just 2

• reduced recency effect

• largely functioning LTM

Population dissociations

• when populations differ on one measure, but don’t differ (or differ in the opposite way) on another measure

interpretation of population dissociations

• commonly interpreted as evidence for separate brain systems

• there is a damaged system that is responsible for the deficient form of memory

• there is a second, intact system that is responsible for the functioning form of memory

Henry Molaison revisited, what was he able to do

• he was able to learn motor skill but have no recall for learning it

• backwards mirror skill

Priming

• showing long-term memory for the prior experience

• exposure to an initial stimulus unconsciously influence how you respond to a later stimulus

• implicit memory

Fragment completion

• gave fragments that could be completed by earlier words

• can therefore examine memory in the form of priming

Graf et al. (1985) results

• poor memory when consciously trying to use memory on free recall test

• normal memory when not consciously trying to use LTM on the fragment completion test

Spontaneous productions

• priming

Explicit vs. implicit memory

conscious vs. not conscious

Explicit memory

• episodic (personal facts)

• semantic (facts, knowledge)

Implicit memory

• priming (spontaneous productions)

• procedural (skill learning)

• conditioning

Direct tests

• directly refers to a past event

• aware that using memory

• free recall, cued recall, recognition

Indirect tests

• do not refer past events

• no mention of memory

• simply ask to perform current task

Converging evidence

• population dissociations

• experimental dissociations

• developmental dissociations

• drug-induced dissociations