Memory theories + case studies Flashcards
Who is HM and what happened to him?
- had severe epilepsy
- hippocampus removed to prevent seizures
How did the removal of the hippocampus affect HM?
unable to form new long term memories
Who was HMs main researcher?
Millner
What did Millner discover about HM?
able to learn skills (procedural memory) by tracing shapes but had no conscious recollection he learnt them (declarative memory)
STM capacity
Who made the digit span technique for stm?
Jacobs 1887
STM capacity
What is the digit span technique?
- read aloud a list of letters of numbers
- increase leangth of list until recall is wrong 50% of time
STM capacity
What were the results of the digit span technique?
- stm capactity for digits was 9 and for letters 7
- concluded age doesnt affect stm
- avg digit span 5-9
- number easier to recall than letters
STM capacity
Who divised the ‘magic number’ theory?
MIllner 1956
STM capacity
What is the ‘magic number’ theory?
- belief that memory is determined by chunks of info
- noted things come in 7s so number capacity in stm is around 7
- also people can recall 5 words as well as 5 letters
STM capacity
What did Cowan (2001) conclude about capacity?
Capacity of STM is around 4 chunks
STM duration
Who did the trigram study?
Peterson and Peterson
STM duration
What was the trigram study?
- test 24 students in 8 trials
- give consonant trigrams (non pronouncable letters like LDH)
- had to recall after intervals of 3,6,9,12,15,18 seconds
STM duration
What were the findings of the trigram study?
- participants able to recall 80% after 3 secs
- as intervals increases recall declined
- by 18 secs only recall 10% or less
- concluded recall decays rapidly when rehersal is prevented
What was the evaluation of the trigram study?
- artificial so lacks mundane realism
- doesnt reflect real life memory activities so lacks external validity
STM encoding
What did Conrad (1964) do?
showed participants a random 6 letter sequance and projected them rapidly onto a board and then immediately asked them to recall
STM encoding
What were the 2 conditions of Conrads study?
- acoustically similar (BCTGDV)
- acoustically dissimilar (FJXMSR)
What did Conrad find?
- Ps frequently made errors by substituting similar soundsing letters (V for a D)
- due to substitution errors and acoustic confusion
What is the evaluation of Conrads study?
- well controlled lab exp
- artificial stimui so lacks relaism and external validity
- use of students lacks population validity
- too simplistic
Who was KF?
- motorbike accident damaged temporal lobe
How did the injury affect KF?
short term memory for digits was poor when read aloud (acoustic) but recall was better when reading digits (visual)
suggests there are seperate stores for visual and auditory
MSM
What did Craik and Lockhart say about MSM?
things are remembered better if processed semantically
MSM
What did Craik and Tulving say?
elaborate rehersal is needed for encoding into LTM
Types of LTM
What was the study of Rosenbaum 2005?
- motorcycle accident left with brain damage
- large bilateral hippocampus leisions
- general knowledge (semantic) intact but recalling personal events was impared (episodic)
- ‘episodic amnesia’
- shows episodic and semantic are 2 different processes
Episodic and semantic
What did Tulving do 1989?
- performed brain scans on 6 voulenteers
- when episodic memory used the frontal cortex was active
- when semantic used the back of the cortex was active
- backs up that semantic and episodic are seperate
What was the aim Underwood and Postmans study 1960?
-to find out if new learning intereferes with previous learning
What was the procedure of underwood and postmans study?
- Ps divided into 2 groups
- Group A learnt a list of word pairs and in the second list the second word in the pair was different
- B asked to learn first list only
- both groups asked to recall first list
What were the results of Underwood and postmans study?
B recalled first list more accurately than A
What did Underwood and Postman conclude?
learning items in 2nd list interfered with ability to recall which is retroactive interference
What was Godden and Baddeleys aim (1975)?
to investigate the effect of the environment on recall
What were Godden and Baddeleys conclusions?
being in the same environment for recall and learning is beneficial
What was Godden and Baddeleys procedure?
- 18 divers asked to elarn a list of 36 unrelated words of 2 or 3 syllables
What is the evaluastion of Godden and Baddeleys study?
- atificial
- controlled so easy to replicate. so reliability can be tested
What were Godden and Baddeleys 4 conditions?
- learn on beach and recall on beach
- learn on beach and recall underwater
- learn underwater and recall underwater
- learn underwater and recall on beach
What were the results of godden and baddeleys study?
