7. Learning and Memory Flashcards
Def of learning
A process that expresses itself as an adaptive change in behavior in response to an environment
Def of memory
The encoding, storage, and retrieval of info about past experience– necessary for learning to take place
Patient H.M.
Suffered from severe epilepsy
Couldn’t form new memories, but retained short-term info
Retained unconscious muscle memory
Discovered that memory for facts (names, dates, facts) is different than procedural memory (riding a bike, walking, driving)
Knowing fact vs. knowing how
Short-term vs. long-term memory
Patient H.M. helped us discover this differentiation
Retrograde amnesia
Loss of memories formed prior to onset of amnesia
Anterograde amnesia
Inability to form new memories after the onset of the disorder
Declarative memory
Facts and info acquired from learning
Ex: knowing the capital of France
Nondeclarative memory
Shown by performance rather than recollection
Ex: riding a bike
H.M. star tracing task
H.M. was able to improve his motor skills with practice but did not remember all of his attempts
Showed difference between factual memory and procedural memory
Hippocampal formation
Composed of hippocampus, parahippocampal gyrus, subiculum, and entorhinal cortex
All play significant roles in memory formation
We know the hippocampus is involved because of patient H.M.
Key lessons from H.M.
Could remember things for a short time
The distinction between short-term and long-term memory
Without a hippocampus, H.M. was unable to form new declarative memories
The hippocampus is crucial for declarative memory formation
H.M. retained memories from early childhood
Able to form new procedural (non-declarative) memories
Supported by basal ganglia and cerebellum
Testing declarative memories in animal models
Delayed non-matching-to-sample task: a test of object recognition memory, where the monkey must choose the object that was not seen previously
Patient K.C.
Suffered brain damage from motorcycle accident
Wasn’t able to retrieve memories from his past (personal declarative or “episodic” memory)
He still retained generalized declarative memory
Showed cortex is essential for long-term memory
Two subtypes of declarative memory
Semantic memory
Episodic memory
Semantic memory
Generalized memory
Episodic memory
Detailed autobiographical memory
Personal experiences and specific events with details about the time and place they occurred
Three types of nondeclarative memory
Skill learning
Priming
Associative learning
Skill learning
Learning to perform a task requiring motor coordination
Don’t need to think about what you’re doing (ex: driving)
Priming
Repetition priming
Prior exposure to a stimulus changes the way you respond later
Associative learning
Relationships between things in the environment
Ex: backpack and school
Classical and operant conditioning
Classical conditioning
Pavlov’s dogs
Food, salivating, bell
Repeated pairings
Timing matters– two stimuli need to happen at the same time
Bell then food immediately after
Operant conditioning
Associate actions with rewards or consequences
Long-term memory
Can last for days or years
Not meant for us to recount our complete life stories, just important events to shape our future behavior in adaptive ways
Important component is forgetting– pruning of unimportant memories to preserve cognitive resources
3 stages of long-term memory
Encoding
Consolidation
Retrieval
Encoding
When sensory info is brought into short-term/working memory
Ex: learning in lecture
Consolidation
Transferring info from short-term memory to long-term storage
Ex: studying for a test
Retrieval
Taking memory out of long-term storage
Ex: taking a test
Neuroplasticity
Neurons and neural circuits remodel in response to experience or the environment
The Synaptic Plasticity Hypothesis
Synapses between neurons can be created and modified by experience
Synapses can weaken and strengthen
Ex: forgetting your hometown roads when you leave for college
Changes in synapses can be measured…
Physiologically
May be presynaptic, postsynaptic, or both
Increased neurotransmitter release or changes in neurotransmitter-receptor interactions
Structural changes to the synapse
New synapses could form with training/use, or some could be eliminated with lack of use
Training might lead to synaptic organization
Synaptic organization
Altering the structure of the circuits; alter how your brain is communicating
Rearrangement of synapses
Hebbian synapses
Donald Hebb: “Cells that fire together, wire together”
If a presynaptic neuron repeatedly activates a postsynaptic neuron, connection becomes stable and strong
Cell assemblies
Groups of neurons
Act together to store memories
Long-term potentiation
Increase in effectiveness of synapses, which causes addition of AMPA receptors on the postsynaptic membrane
Long-term depression
Weakening of synaptic efficiency
Animals housed in enriched condition compared to those in impoverished condition developed:
Heavier, thicker cortex
Enhanced cholinergic activity
More dendritic branches with dendritic spines
