What are the 3 different memory systems?
- declarative memory (S-S)
- procedural memory (S-R)
- emotional memory (S-effect)
- form of S-S
Which parts of the brain does declarative memory use?
medial temporal lobe and diencephalon
What make up declarative memory?
facts and events
What make up non-declarative memory?
Procedural memory - skills and habits
Classical Conditioning
- skeletal musculature
- emotional responses
What type of memory system did HM lack?
- amnesic patient
declarative
HM’s memory disorder was selective in 5 different ways:
- higher-order perceptual, motor, cognitive functions not affected
- above average IQ
- recognizes and names common objects
- normal language - Lost the capacity for new learning
- he scored 0 on tests that tested the persistence of his memory (stores, lists, pictures)
- anterograde amnesia
- limited amount of retrograde amnesia - the “span” of short term memory was normal, but devastated by delays
- size of working memory was not affected, but memories would just dissipate rathe than being transformed to short term - spared remote memory
- spared other domains of learning and memory capacity
- sensory motor learning
E.g. Mirror drawing task - get better with practice; HM could do this but couldn’t remember ever performing the task
E.g. basic image repeat - HM could do this but couldn’t remember ever completing the task
What is anterograde amnesia?
inability to create new memories
What is retrograde amnesia?
forgetting wheat happened in the past
Explain verbal priming
Word stem completion task
- ask subject to remember words
- test knowledge in different ways
- -> free recall
- -> cued recall (e.g. a place that you sleep)
- -> completion (e.g. give beginning of word)
What is habitual learning?
association of specific patterns of visual stimuli with specific motor sequences
What type of memory system is involved in the formation of habits?
Declarative
What is declarative memory?
facts and events that require conscious recollection and that can be expressed explicitly
What is procedural memory?
skills and preferences that can be acquired and expressed unconsciously
Problems associated with changes to the brain
- anatomical specificity (e.g. damage is never very specific to the hippocampus)
- unknown experiences (e.g. cab drivers in London have larger hippocampi)
Why are animal studies useful?
able to control for experiences and make selective lesions
What is the procedural memory system?
transition from one memory system to another (hippocampus –> striatum)
Explain the cognitive map - Edward Tolman
“Response” or “place” strategies?
- S-S = spatial
- S-R = just turn right towards the door
To test: turn maze around
- initially rats use spatial learning (hippocampus)
- but with time, most choose place strategy and choose the door rather than going right (striatum) = habit
What is the striatum involved in?
regulation of voluntary movements; planning, initiation and learning motor behaviour
- abnormalities or lack of dopamine to this area –> Parkinson symptoms
Explain “from place to habit response”
Perceptual learning task (e.g. predict rain or shine using deck of 4 cards)
- practice –> perfect (eventually determine pattern)
- Parkinson’s never learn
- amnesia (HM) does (though he doesn’t recall)
= DOUBLE DISSOCIATION
Injections of lidocaine:
- lesions to hippocampus
- no place preference - lesions to the striatum
- all place preference
- removed ability to perform habit
What is double dissociation?
2 tasks, 2 regions and interaction between the 2
What brain structure is important in emotion?
amygdala
What is the amygdala responsible for?
Displaying proper emotion with proper stimulus
Which part of the amygdala is referred to as the learning center?
basal-lateral amygdala
- fear conditioning
- incentive/place preference conditioning
Explain Antonio Damask’s study of 3 diseases
Patient 1 - Urbach-Wiethe disease
- calcification of the amygdala (death of tissue)
- selective region to amygdala
Patient 2 - hypoxia/ischemia
- less oxygen/blood to the brain
- apoptosis = destruction of cells
- selective hippocampus lesion
Patient 3 - herpes
- destruction of temporal lobe
- amygdala and hippocampus gone
Skin conductance results:
Control
- US –> sweat
- unpaired stimuli –> NR
- paired CS –> sweat
Amygdala lesion
- US –> sweat
- after conditioning –> NR (can feel emotion and respond but don’t respond to CS)
- what colour is this? - can list colour, details of conditioning component, but cannot display CR
Hippocampus lesion
- shows UR and CR
- What colour is this? “colour????”
Lesions to both
- comparable to amygdala lesion - driving the effect
- no CR
–> memory systems work in parallel and are not dependent on each other
