Chapter 13: The Biology of Learning and Memory Flashcards
Classical Conditioning
-pairing two stimuli changes the response to one of them
-Pavlov’s dog
CS+UCS=UCR (initially)
Bell + Meat = Salivation
CS -> CR
Bell -> Salivation
Operant/Instrumental Conditioning
-individual’s response leads to reinforcement (increases future probability of response) or punishment (decreases frequency of response)
describe Lashley’s search for the engram
- Lashley reasoned that if learning depends on new or strengthened connections between 2 brain areas a knife cut somewhere in the brain should interrupt that connection and abolish learned response
- no knife cut significantly impaired learning
- also found lesions impaired performance but deficit depended more on amount of damage than location
engram
- physical representation of what has been learned
ex) connection between 2 brain areas
Lashley’s 2 principles
equipotentially- all parts of cortex contribute equally to complex behaviours such as learning and any part of the cortex can substitute for any other
mass action- cortex works better as a whole and more cortex is better
2 Unnecessary assumptions for Lashley’s findings
1) cerebral cortex or only place to search for engram
2) all kind of memory are physiologically the same
Richard Thompson
- studied classical conditioning of eyelid response in rabbits
- LIP (lateral interpositus nucleus) essential for learning
- when LIP was suppressed learning had no effects
characteristics of short-term memory
- maximum capacity
- depends on rehearsal
- forget something=lost forever
- emotionally significant memories form quicker
characteristics of long-term
- vast difficulties to estimate capacity
- can recall long term memories you haven’t thought about in years
- hint can help reconstruct something you thought you forgot
characteristics of working memory
- way we store info while we are working with it
- test=delayed response task
- older people have impairments of working memory due to changes in prefrontal cortex
describe the theories of the function of the hippocampus in declarative memory, spatial memory, context learning, and consolidation
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Declarative memory
- hippocampus is critical for declarative memory (especially episodic)
- hippocampal damage impairs delayed matching and nonmatching to sample task (remembering object that was present in an occasion)
Spatial Memory
- when people perform spatial tasks fMRI results show enhanced activity in hippocampus (visualizing a route from one place to another)
- MRI scans showed taxi drivers have larger than average posterior hippocampus (directly proportional to length of time as taxi driver)
- shows growth of hippocampus in response to spatial learning activities
- maze activities- people/rats with damage have trouble remembering where they have already been
- species comparisons show link between hippocampus and spatial memory
Contextual memory
Hippcampus-important for remembering details and includes lots of detail, as time passes memory becomes less detailed and more dependent on cerebral cortex
Consolidation
- small to moderate amounts of cortisol activate amygdala and hippocampus where they enhance storage and consolidation of recent experiences
- amygdala in turn stimulates hippocampus and cerebral cortex (both important for memory storage)
- prolonged stress (increase cortisol) impairs memory
- consolidation can be fast or slow and depends on more than time necessary to synthesize new proteins
causes of Korsakoff’s syndrome
Cause-
- brain damages caused by prolonged thiamine deficiency
- chronic alcoholic
- deficiency leads to loss of shrinkage or neurons in brain
Most affected brain area in Korsakoff’s syndrome
-most affected area=dorsomedial thalamus
Symptoms of Korsakoff’s syndrome
- apathy, confusion, memory loss
- distinctive symptom=confabulation (mainly for episodic memory questions)
Alzheimer’s Disease
- better procedural than declarative memory
- memory and alertness vary substantially suggesting problems results from malfunctioning neurons rather than neuron death
- gradually progresses to more serious memory loss, confusion, depression, restlessness, hallucinations, delusions, sleeplessness, loss of appetite
Genetic link to Alzheimer’s
- gene on chromosome 21 linked with Alzheimer’s
- genes to not completely control
Early onset Alzheimer’s damage
- causes protein Amyloid-B to build up inside and outside neurons
- damage varies but net effect=damage to dendritic spine , decrease synaptic input and decreased plasticity
- damage from amyloid clusters into plaques
- plaque accumulate- in cerebral cortex, hippocampus and other areas atrophy
Tau protein and Alzheimer’s
-becomes altered with more phosphate groups causing them not to be able to bind with usual targets within axons and results in spreading to cell body and dendrites=magnifies damage
other brain areas that contribute to various aspects of memory
- gradual learning depends on basal ganglia (implicit or abit learning)
ex) what a basketball player on another team is most likely to do in a situation so you can guard better
Basal ganglia contribute to memory
-important for procedural memory
