Lecture 14 & 15: McDearmid Flashcards
Define learning:
A change in behaviour as a result of experience with a specific stimuli. - Allows for appropriate behavioural responses to a stimulus.
Define memory:
Storage and the ability to recall experiences
Why use aplysia californica to study learning and memory?
Simple model, Easy to observe response, easy to experiment on
Why is aplysia californica a simple model
Only 2x10^4 cells in nervous system (reductionist) Cells are up to 1mm (very large) Many cells are identifiable and invariant as unique individuals.
Why is aplysia californica easy to observe and measure responses
Respiratory appartus (gill, siphon) has distinct withdrawal response- withdraws into mantle cavity for protection when exposed to tactile stimulation
Why is aplysia californica easy to experiment on?
Place on top of a photocell (photocell under gill) When gill is withdrawn light can pass through –> measurement of withdrawal
What is non-associative learning?
A change in response strength due to prolonged exposure to a stimulus?
What are examples of non-associative learning?
Habituation: experience leasd to decreased response strength (repeat innocous stimulus) Dishabituation: restoration of a habituated response due to a novel stimulus Sensitisation: increase in strength of a response following a strong novel stimulus
How does the gill siphon withdrawal reflex habituate?
Gentle tactile stimulation to the siphon every 90 secs –> decreased withdrawal INSERT DIAGRAM
![](https://s3.amazonaws.com/brainscape-prod/system/cm/143/619/099/a_image_thumb.png?1659462352)
How does the gill siphon withdrawal reflex display dishabituation?
Novel stimulus (shock) applied to the tail following habituation to tactile stimulus) –> increased withdrawal
What is associative learning?
Classical conditioning: Present a conditioned stimulus (siphon stimulation) and pair this with an unconditioned stimulus (tail shock) Measure response of unconditioned stimulus alone
How has associative learning been tested with aplysia californica?
Pair siphon stimulation with tail shock –> measure response to tail shock alone Unpaired CS and US –> measure response Apply tail shock –> measure response
What are the results of associative learning experiments on aplysia californica?
Insert diagram - Paired response is the strongest —> increased strength response is retained for roughly 4 days due to memory?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/143/619/874/a_image_thumb.png?1659462353)
How do the intervals between the stimuli affect results?
The unconditioned stimuli will not be associated with the conditioned stimulus if it is applied before or if it is over 2 seconds after. The interval which provokes the strongest learning response is 0.5s
Define short term memory:
temporary storage of information relating to an event that has just occured