STM & Working Memory Flashcards
STM
a temporary store in which we integrate current sensory experience with long term memory to achieve current goals
Capacity of STM
limited
Duration of STM
15-30 seconds
How is verbal STM capacity assessed?
using digit-span task
Explain the digit-span task
- immediate serial recall of verbally presented digits in the order they were presented
- systematically increase length of sequence to determine the “span”
- a participant’s span is reached when they fail on 2 trials at a given series length
Average span
7 +/- 2
How was duration of STM assessed?
The Brown Peterson task
Explain the Brown-Peterson task
- remember 3 consonants
- memory probed (tested) at 3 second retention intervals
- to prevent rehearsal, participants were required to count backwards in 3’s until given a signal to stop
What are serial position effects?
the psychological tendency to remember the first and last items in a list better than those in the middle
Explain serial position effects
- immediate free recall of lists of numbers of words is affected by position of items in list
PRIMACY EFFECT (more rehearsal)
RECENCY EFFECT (still in STM)
How is the recency effect reduced?
by introducing a filled retention interval
How is the primacy effect eliminated?
introducing a concurrent task (e.g. repetition of a word)
Craik & Tulving (1975) - Levels of Processing
test the idea that LTM for words is influenced by the “depth” of the encoding process used in STM
What is the central executive?
responsible for controlled processing in working memory - directs attention to & retrieves info from PL & VSS for integration in the episodic buffer
What is the phonological loop?
a mental workspace for manipulating auditory & verbal info
What is the digit-span backwards?
a test of phonological / verbal working memory because you must actively manipulate info in memory rather than just maintain the sequence
What is the visuo-spatial sketchpad?
a temporary store for representations of visual & spatial info such as faces, objects, written words & cognitive maps
- allows you to manipulate visually & spatially represented info
- e.g. mental rotation of objects
What are executive processes?
- used in planning & coordinating behaviour (e.g. goal orientation)
- governed by circuitry in pre-frontal cortex, especially dorsal prefrontal cortex & anterior cingulate cortex (ACC)
Which area of the brain governs the phonological loop?
left-hemisphere fronto-temporal lobe network
Which area of the brain governs the visuo-spatial sketchpad?
right occipital-parietal network
Which area of the brain governs the episodic buffer?
the parietal cortex
