Memory

Atkinson and Shiffrin

Information flows through memory

Three stores linked by processing

• sensory registrer
• STM
• LTM

Supporting research evidence

• Baddeley 

There is more than one type of STM

• patient KF

There is more than one type of rehearsal

• Craik and Watkins

a stimulus from the environment will pass into the sensory register along with lots of other senses

not a single store but several, one for each sense

iconic- visual 

echoic- acoustic

duration is less than half a second

high capacity- one million cells in one eye, each storing data

very little of what goes into the sensory register passes into the memory system

the key process is attention

limited capacity store

can only contain a number of 'things' before forgetting takes place

capacity of stm is between 5 and 9 (7+2)

STM coded acoustically 

lasts for 30 seconds unless rehearsed 

maintenance rehearsal occurs when we repear material to ourselves over and over again

if rehearsed long enough it passes to the LTM

potentially permanent memory store for information that has been rehearsed for a prolonged time

capactiy is unlimited

last for many years

Bahrick- school year book study

LTM coded semantically

when we want material from LTM has to be transferred back onto STM by retrieval

no memories are recalled directly from LTM

supporting evidence

• STM and LTM are indeed qualitatively different
• Baddeley
  • when using STM muddle up similar sounding words
  • when using LTM muddle up similar meaning words
• coding in STM is acoustic and LTM is semantic
• seperate stores and independent

there is more than one type of STM

• amnesia patients- KF
• STM recall for digits was poor when spoken but when looking at them he could recall much better
• there must be at least one STM store for visual and another for auditory information- WMM

Tulving

MSM too simplistic

three LTM stores:

• episodic memory
• semantic memory
• procedural memory

clinical evidence

• HM and Clive Wearing

neuroimaging evidence

• brain scans

real-life application

• Belleville et al (2006)

ablity to recall events from our lives

likened to a diary, a record of daily happenings

complex

time-stamped, a single epsiode will include several elements: people and places

concious effort to recall episodic memories

can be done quickly but you are aware of the doing so

knowledge of the world

facts- in a broad sense

likened to an encyclopedia and a dictionary

not time-stamped

less personal and more about facts we share

contains an immesnse collection of material that is always being added to 

actions, skills and how we do things

we can recall these without concious awareness or effort

these are skills that can be difficult to explain to someone else, describing the task whilst doing it can make it the task more difficult

clincal evidence

• HM and Clive Wearing
• episodic memory severely impaired due to amnesia
• difficult to recall past memrories
• semantic memories unaffected- still knew what a dog was
• procedural memories unaffected- tie shoelaces, walk and speak- CW could read and play music
• support Tulving

Neuroimaging evidence

• brain scans
• Tulving got ppts to do tasks whist having a PET scan
• episodic and semantic memories both recalled in the prefrontal cortex (left= sem, right= epi)
• later research studies supporting the validty of this finding

Real-life application

• Belleville et al (2006)- episodic memories can be improved in older people who had mild cognitive impairment
• episodic memory is most affected
• highlights the benefit of being able to distinguish between types of LTM- enables  specifictreatment to be developed

There is more than one type of rehearsal

• Craik and Watkins
• maintenance rehersal (MSM) does not transfer information into LTM just maintains it in STM
• elaborative rehearsal is needed for LTM storage, link the information to exsiting knowledge