Learning and Memory - Chapter 13

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Module 13.1 Learning, Memory, Amnesia, and Brain Functioning (p374-391) Localized representations of memory (p374-377) Classical Conditioning:

Classical conditioning: pairing two stimuli changes the response to one of them

Conditioned stimulus (CS): initially elicits no response

Unconditioned stimulus (UCS): automatically elicits an Unconditioned Response (UCR)

Conditioned Response (CR): a new, learned response to the CS, after pairing the CS with the UCS

UCR turns into CR after training

Operant conditioning:

Operant conditioning: an individual's response leads to a reinforcer or punishment

Reinforcer: an event that increases the future probability of the response

Punishment: an event that suppresses the frequency of the response

Reinforcers and punishments can both be positive or negative

Main difference between operant and classical is that operant conditioning is dependent on the individual's behavior, where classical is not; i.e. presentation of a CS or UCS regardless of any initiating behavior vs. behavior leading to punishment or reinforcer

Lashley:

Engram: physical representation of what has been learned

Lashley looked for strengthened connections or new connections made in cortex during learning

Equipotentiality: all parts of the cortex contribute equally to complex behaviors such as learning, and any part can substitute for any other

Mass action: the cortex works as a whole and more cortex is better

Thompson:

used a simpler task than Lashley to find engram of memory

Looked in the cerebellum instead of cortex

Lateral Interpositus Nucleus (LIP): in cerebellum; essential for learning; activity in LIP increases as learning progresses; training did not progress while LIP was suppressed

Red Nucleus: training took place while red nucleus was suppressed, learned response exhibited once red nucleus recovered

LIP is necessary for learning and retention

Types of memory (p377-379) Short-Term vs. Long-Term Memory:

Short-term memory: events that have just occurred

Long-term memory: events from further back

S-T and L-T differ in their capacity

S-T memories fade quickly unless rehearsed

S-T memories are lost once forgotten, L-T memories can be stimulated into recall

Researchers proposed that memories stayed in S-T until consolidated into a L-T memory, if rehearsal is interrupted before consolidation takes place, information is lost

Working memory: alternative concept to S-T memory that emphasizes that temporary storage is not a station on the route to L-T but the way we store info while we are working with it. Example: delayed response task

Potential hypothesis: Prefrontal cortex stores temp info by elevated calcium levels which potentiate later responses

The Hippocampus and Amnesia (p379-387) People with Hippocampal Damage:

Hippocampus important and active during formation of memories and later recall

Amnesia: memory loss

Retrograde amnesia: loss of memory for events that occurred before the brain damage

Anterograde amnesia: inability to form memories for events that happened after brain damage

Short-term memory remains intact

Impaired storage of long-term memory

Can still "learn" using working memory frequently rehearsed (e.g. a name heard frequently on the news or self-devised labels)

Episodic memory impaired: memories of single events; might remember facts learned before damage but not recall any specific events either before or after damage