Week 10: Learning & Memory Flashcards
Learning
Process by which experiences change our nervous system and hence our behaviour
Theories of learning
Classical Conditioning*
Operant Conditioning*
Perceptual Learning
Relational Learning
classical conditioning
all behaviours are acquired through conditioning that occurs through interactions with the environment
operant conditioning
the effects of a particular behaviour (i.e., the reinforcers) in a particular situation increase or decrease the probability of the behaviour in the
future
* Modification of voluntary (or “operant”)
behaviours
* Use of punishment (to decrease future behavior) or reinforcement (to increase future behavior)
reinforcement
a consequence that causes a behaviour to occur with greater frequency
punishment
a consequence that causes a behaviour to occur with decreased frequency
continuous reinforcement
The desired behavior is reinforced every
single time it occurs.
● Best used when first learning to create a strong association between the behavior and response.
●E.g., training your dog to sit with biscuits
Intermittent reinforcement
Once the response is established. The response is reinforced only part of the time.
●Learned behaviors are acquired more slowly, but the response is more resistant to extinction.
●Fixed-ratio or Variable ratio (# responses)
●Fixed interval or Variable interval (amount of time)
perceptual learning
- Perceptual Learning involves learning to recognize things;
- It involves perceptual changes from practice or experience.
- Differentiation; unitization; stimulus imprinting; attentional weighting
relational learning
- Most learning is more complex than simple Stimulus-Response associations
- Involves learning the temporal and spatial relationships among objects and events
STM VS. LTM
●Short-term memory has a limited capacity; long-term memory does not
●Short-term memory fades quickly without rehearsal; long-term memories persist
●Long-term memory can be stimulated with a cue/ hint; retrieval of memories lost from STM do not benefit from the presence of a cue
●STM usually described in more contextual detail than LTM
Long-term memory (LTM)
- LTM: Theoretically unlimited capacity for
indefinite period of time - Physiologically, it is thought that long term
memories are formed through long-term
potentiation (LTP) - The hippocampus plays a role in converting
memories from STM to LTM - Emotionally significant information is more
likely to be stored in LTM - Locus coeruleus (NE) and DA projection to
the HC. - Flashbulb memories
Engram
physical representation of what has been learned
Karl Lashley (1890-1958)
- Reasoned that if memories were connections
between brain areas, they could be severed
with a knife - Trained rats on mazes and tasks, then made
cuts to the cortex to try to disrupt performance - Findings?
- Knife cuts did not impair performance
- Therefore, learning and memory did not depend on
connections across the cortex - Also found that learning did not depend on a single area of the cortex – taking out a chunk of cortex impaired performance, but it was about the chunk taken, not the cortical area itself
Equipotentiality
all parts of the cortex contribute
equally to complex functioning behaviors (e.g., learning) and any part can substitute for any other
Mass action
the cortex works as a whole, and more cortex is better
Brain areas of learning and memory
hippocampus
basal ganglia
Hippocampus
- Vital for declarative/episodic memory
- Active during:
●Memory formation
●Memory recall
●Imagining future events
●Important for visual spatial memory
Cells responsible for spatial memory
●Place and Time cells located in the HC = fire in response to spatial locations and temporal information
●Grid cells located in the ERC = hexagonal grid forming a coordinated system that allows for spatial navigation
Basal ganglia
- Basal ganglia involved in implicit learning of patterns and habits
- Implicit learning
- Striatum = caudate nucleus & putamen
Retrograde amnesia
Cant remember life before the injury
anterograde amnesia
Cant make new memories
korsakoffs syndrome
- Thiamine deficiency (common in alcoholism)
- Loss of neural activity throughout the brain, esp. dorsomedial thalamus
- Hallmark: confabulation (“honest lying”
Hebb’s rule
“Any two cells or systems of cells that are repeatedly
active at the same time will tend to become ‘associated’, so that activity in one facilitates activity
in the other.”
A basic mechanism for synaptic plasticity wherein an
increase in synaptic efficacy arises from the presynaptic cell’s repeated and persistent
stimulation of the postsynaptic cell.
“Cells that fire together wire together!
