Paper 1- Memory Flashcards
What is the duration of the STM? Give supporting research
Peterson and Peterson studied 24 ppts in a lab and showed them nonsense syllables followed by 3 digit numbers that they had to count back from (articulatory repression).
Counting for 3 seconds: 90% of syllables remembered
Counting for 18 seconds: 2% remembered
Suggests STM has a short duration if rehearsal is prevented
- lacks mundane realism (all artificial tasks) which are meaningless
- could have been displacement; numbers may have replaced the syllables rather than decay (lack of validity) - other researchers found up to 96 seconds
What is the capacity of the STM? Give supporting research
Miller found 7+/-2
However it could be limited to around 4 chunks of info for visual rather than verbal stimuli (size of the chunk also matters)
- also individual differences - may increase capacity steadily with age (due to brain/strategy development)
Supported by Jacobs et al - digit span test with every letter except those which had two syllables - people found it easier to recall numbers rather than letters - letter was 7-3 but numbers 9-2
STM encoding?
largely encodes acoustically (so it is better at remembering semantically similar words)
What is the duration of the LTM?
Barrick et al tested 400ppts in a natural experiment based on their ability to remember their classmates in their yearbook from photo-recognition
After 15 years: 90% recognition
After 48 years: 70%
Suggesting it could be potentially limited
- this experiment was high in ecological validity due to meaningful results
Capacity of LTM?
Unlimited
Encoding of LTM?
Semantic encoding (remembering acoustically similar better)
Describe divisions in the LTM
Episodic (explicit)
- remembering an event concerned with personal experiences (feelings, surroundings)
Semantic (explicit)
- knowledge that may be shared by everyone (function, abstract concepts, general knowledge)
- tend to begin episodic as we gain knowledge off of personal experience
Procedural (implicit)
- concerned with skills and remembering how to do something
- automatic function (over-attention may disrupt it)
Give evidence for research into the LTM divisions
Evidence to support:
- Distinction made between the three types (they originate in different parts of the brain). Tested through brain scanning and found hippocampus: episodic, temporal: semantic, cerebellum: procedural
Distinguishing between procedural and declarative:
- case study of HM who had a damaged hippocampus and parts of the temporal lobe - retained pre-existing LTM’s but could not form new ones : form new procedural but not semantic and episodic (showing different areas) - idiographic?
Distinguishing between episodic and semantic:
— Hodges et al found that episodic could be formed without semantic showing a single dissociation in Alzheimers patients (however insufficient evidence as episodic memory places greater demands for mental processing so damage would be more detrimental)
- Irish et al therefore found second dissociations in Alzheimer’s patients demonstrating poor semantic but intact episodic showing the gateway but ability to form semantic separately
- Tulvings PET scans found that left prefrontal cortex semantic and right prefrontal cortex episodic
Describe the assumptions of Alkinson+Shiffin
Suggested to be 3 distinct/separate stores where information mores in a linear direction
- SENSORY to STM to LTM
maintenance rehearsal between STM and LTM
Sensory: modality specific - iconic and echonic stores , 1/2 second duration but unlimited capacity
Evaluate research into the MSM
Supporting lab evidence
- Brain scanning techniques demonstrating that the that the LTM triggers activity in the hippocampus and STM in prefrontal (distinct and separate) - objective but artificial tasks
Too simple
- theory assumes ‘unitary’ stores but unsupporting research from Baddeley and Hitch who suggested that the STM was split further in different functioning stores - same in LTM (maintenance rehearsal would only explain semantic)
Involves more than maintenance rehearsal
- Lockheart et al: memories are processed deeply or shallowly (more memorable is deeper processing) - easier to remember words when they were in sentences rather than out of context words
Case study support Scoville and Milner
- HM brain damage; retained personality but hippocampus damage from surgery stopped formation of LTM (shows distinct stores but idiographic)
Describe the WMM
Baddeley and Hitch assumed that the STM was split into further stores and dual tasks between the stores often resulted in interference
- central executive: master store which directs attention to particular tasks, data arrives from LTM of senses with a very limited capacity
Phonological loop: Limited capacity but deals with and processes auditory info (phonological store=holds words you hear, articulatory processes= words you read)
-Visuo-spatial sketchpad: Used when you have to plan a spatial task (visual cache=info about visual items, inner scribe=deals with spatial relationships and arrangement)
- Episodic buffer: general store - both visual and acoustic info and integrates from all stores , maintains sense of time sequences
Evaluate research into the WMM
Research:
- gave ppts two tasks (1 occupied the central executive and 2 was either articulatory loop/ central exec
- efficient when different but interference and unsuccessful when they were the same (lacks ecological)
Evidence from brain damaged patients:
Shallice and Warrington - studied KF who forgot auditory stimuli more than visual but his auditory problems were limited to verbal material rather than meaningful sounds (showing the damage was only limited to phonological and not episodic; separate) - idiographic
AND… the process of brain injury is traumatic and may itself change performance - difficulty paying attention may compromise memory
Lack of clarity
- Baddeley recognised that the central executive
- underexplains
Braver
- brain scanning- left prefrontal cortex, increased activity when task became harder as it demands on the CE
What is interference? (forgetting)
- explanation of forgetting in terms of one memory disrupting the ability to recall another (most likely when the memories are similar)
Explain retroactive interference
Retroactive - Muller - current attempts of learning interfere with past learning:
- current attempts of learning interfere with past learning
- gave ppts list of nonsense syllables to learn for 6 mins, intervening task and recall - poorer performance if there was an intervening task as it interfered with past learning
Explain proactive interference
Underwood- past learning interferes with current attempts of learning
- analysed a range of studies and found that when participants had to learn a series of word lists, they were stronger in the middle (10 lists only 20% remembered but 1 list is 70%)