learning & memory Flashcards
learning
the process of acquiring information
memory
the ability to store and retrieve that information
patient H.M.
Henry Gustav Molaison (1926-2008)
- bicycle accident when young led to the development of severe epilepsy
- at 27, surgeon removed parts of his brain in an attempt to stop his seizures
bilateral medial temporal lobectomy
removal of the medial portions of both temporal lobes, including most of the hippocampus, amygdala, and adjacent cortex
positive results of H.M. surgery
- general convulsions eliminated
- partial seizure frequency decreased
- anti-convulsant medication decreased
- no change to perceptual nor motor abilities
- slight increase in intelligence
consequences of surgery
- mild retrograde amnesia - limited memory of events in the 2 years preceding surgery
- severe anterograde amnesia - difficulty forming some new long-term memories
- profound deficits in long-term declarative memory (explicit)
retrograde amnesia
loss of memories formed before a brain injury
anterograde amnesia
- loss of memory for things occurring after a brain injury
- inability to make new memories
memory tests
- mirror drawing task
- incomplete pictures task
amnesia
severe impairment of memory
types of non-declarative memory
- skill learning (sensorimotor)
- priming
- associative learning
- classical conditioning
- instrumental conditioning
skill learning
** process of learning how to perform a challenging task by simply doing it over and over again
- does NOT require the medial temporal lobe
- does require the basal ganglia, cerebellum, and motor cortex
priming
** a change in the way you perceive a stimulus, specially because you’ve seen it or something similar before
- associated with reduced activation in the occipitotemporal cortex (word form) or left frontal cortex (word meaning)
associative learning
learning relationships between events
what part of the brain does classical conditioning require?
cerebellum
instrumental conditioning
** learn that a certain action yields a certain consequence
– no consistent brain region identified
- press the lever -> food pellet
poke the nose hole -> get foot shock
classical conditioning
** learning where a person/animal learns to connect two things that happen together
- a bell rings every time food is given, eventually the bell alone can make them expect food
global amnesia
a brief, sudden episode of memory loss that affects the ability to form new memories
scientific contributions from H.M.
- memory functions are NOT diffusely and equivalently distributed throughout the brain
- there are different modes of storage for short-term and long-term memories
- demonstrated a role for medial temporal lobe in memory consolidation
- different mechanisms exist for procedural and non-procedural recall
semantic memory
- general knowledge
(names, dates)
episodic memory
- autobiographical events
(your own experiences)
procedural memory
** long-term memory that helps you remember how to do things, especially physical tasks or routines
- automatic and doesn’t require conscious effort once learned.
ex: tying your shoes/riding a bike
results of delayed nonmatching-to-sample test (monkeys)
loss of the hippocampus, amgydala, and associated cortex in monkeys leads to impairments in object recognition
what parts of the brain are damaged by bilateral medial temporal lobectomy?
hippocampus
amygdala
rhinal cortex
