Lecture 2: the stage theory of memory Flashcards
sensory memory
the short term storage of info from the senses
short term memory
lasts for around 15-20secs and has limited capacity
long term memory
retention for decades, massive capacity
patient H.M (Henry Molaison)
- was having epileptic seizures due to an accident
- had a medial temporal lobectomy = portions of the medial temporal lobes were removed
- frequency of seizures reduced after surgery
- however he was unable to form new memories after the surgery
- this provided evidence for the existence of seperate memory systems
what was the neuropsychological evidence for seperate memory systems
medial temporal lobe damage produces dense anterograde amnesia (LTM) with intact STM
patient K.F
- 28yrs old, accident 11yrs earlier resulted in removal of left parietal subdural haematoma
- LTM tested with incomplete words & pictures test
- LTM is intact and STM is impaired
Atkinson and shriffrins multistore model of memory
sensory memory (300-3000ms) –> short term (20s) —> long term (decades)
the stage theory of memory
sensory memory –> sensory registers
short term memory –> limited capacity (7 plus or minus 2 items), rapid forgetting
long term memory –> massive capacity, very slow (or no) forgetting
the serial position effect
list of 15 words with immediate recall
predicted - the percentage recalled would increase as more words are called eg: the last words called would have the highest chance of being remembered
actual- the earliest and latest words called were remembered
primacy effect
better recall for things early in the list (higher chance of reaching LTM)
Recency effect
better recall for things later in the list (more likely to stay in STM)
bias in encoding (phonetic vs semantic)
a tendency to prioritise either the sound of a word (phonetic) or its meaning (semantic)
phonetic (STM), Semantic (LTM)
- poor recall from STM for words that sound the same
- poor recall from LTM for words that mean the same
Baddely and hitch working memory
predicted = if short term memory is unitary as proposed, then info processing should always be limited to a small no. of items
actual = the recall of info was pretty much equal regardless of how many digits were called
- baddeley and hitch argued the previous model of short term memory is far too simple
4 components in working memory (STM)
- central executive = in command
- visuospatial sketchpad = inner eye
- phonological loop = inner ear and inner voice
- episodic buffer = temp storage, chunking, LTM integration
what is causing memory problems
- it is a processing problem not capacity limitations which is creating these memory problems
how does the working memory model view STM
Views it as a “mental workbench” rather than a storage platform, focuses on the active manipulation of info rather than passive maintenance
chunking
- grouping individual items into larger (and usually more familiar) units of meaning
- this effectively gets around the limited capacity of working memory
maintenance rehearsal - Craik and watkins
- in these models rehearsal is crucial for transfer of info into LTM
maintenance rehearsal = a memory technique that involves repeating info to keep it in STM
