Learning and Memory Flashcards
learning
an adaptive change in behavior as a result of experience
non associative learning
occurs after repeated presentation of a single stimulus
- sensitization
- habituation
sensitization
stimulus that originally elicits no response, repeated presentation leads to heightened responses over time (or one strong presentation–> heightened response)
habituation
learning NOT to respond after repeated presentations/exposures (messages reach the CNS but are ignored)
associative learning
learning about relationships; conditioning
- classical conditioning
- operant conditioning
- appetitive conditioning
- aversive conditioning
- —active avoidance
- —passive avoidance
classical conditioning
Pavlov: UCS, UCR, CS, CR
operant conditioning
aka trial and error learning; animal performs behavior by accident and is rewarded; this behavior is then reinforced as the association builds
appetitive conditioning
reinforcement of a behavior by a positive outcome (think of training a dog with treats)
aversive conditioning
change in behavior to avoid a bad outcome (requires animals to avoid a negative stimulus)
active avoidance
animal must DO something to avoid a negative stimuli (ex: move to the other side of the cage to avoid a shock)
passive avoidance
animal must inhibit/suppress a behavior they would normally perform in order to avoid a more noxious outcome (ex: prefer light to shock)
fear conditioning
depends on the natural state to freeze when frightening
- pair a stimuli with a shock–> elicit freezing behavior
- strength of association between stimuli and shock measured by degree of freezing behavior
memory
encoding, storage, retrieval, or extinction of information about past experience
types of short term memory
working memory, spatial and non-spatial
working memory
short term memory for information that changes on a regular basis
spatial memory
memory of the location of items or places in space
types of long term memory
reference memory, spatial and non spatial
- procedural and declarative
- skills learning, priming, conditioning
- semantic and episodic
reference memory
long term memory for information that is constant/unchanging
procedural memory
implicit long term memory, knowing how
- skill learning: memory for how to perform a skill
- priming: changed memory/processing as a result of previous experience or exposure
- conditioning : formation of an association
declarative memory
explicit memory; knowing what
- semantic memory: knowledge of general knowledge
- episodic memory: knowledge of personal information
water maze
way to measure spatial memory in rats
- rats must swim to find a submerged platform below the surface of the water
- use of spatial memory to locate the platform in relation to its current position with aid of extra-visual cues
water maze and working memory
change the position of the platform in the water maze each day
water maze and reference memory
escape to a hidden platform in a fixed location over days
radial arm maze
way to measure spatial memory in rats
-usually around 8-12 runways)
-baited and non-baited arms
SOLUTION: only 1 trip down the baited arms, avoid the unbaited arms
radial arm maze and working memory
recall which of the arms have already been visited (error= re-entry into an arm)
radial arm maze and reference memory
recall which of the arms are ALWAYS baited
T maze
way to measure spatial memory
-do they always get food on accident, or use cues around the room/maze
Y maze
way to measure spatial memory
-go into the novel arm, should spend more time there
object recognition and object location
ways to measure spatial memory
how are flashbulb memories formed
many hormones released during stress, high arousal may mark the memory’s importance
-Canon’s hypothesis: following exposure to stress, epinephrine is released and acts to enhance memory
EPI: acts on peripheral receptors to influence brain function
evidence
- effects of EPI on L and M can be blocked by adrenergic R’s antagonists
- EPI acts on neural structures that are involved in L and M, including the amygdala
EPI and amygdala
peripheral adrenergic stimulation integrates with teh amygdala
- peripheral EPI acts on noradrenergic R’s which will activate ascending neurons in the vagus nerve–> project to NTS–> project to amygdala
- injection of EPI into amygdala–> increased memory retention
amygdala, hippocampus, emotional valence
degree of amygdala activation by EPI associated with recall, recall best for emotionally intense images/memories
EPI and glucose hypothesis
epinephrine release–> glucose release and increased blood sugar–> enhance L and M
- EVIDENCE
- -can block mem inducing effects of EPI by blocking peripheral adrenergic receptors, but mem enhancing effects glucose not blocked
glucose and ACTH
increased G levels–> increased G to neurons–> release of ACTH
- -EVIDENCE
- glucose treated rats had higher AcTH levels and did better
- ppl with severe memory deficits have marked decreased levels in ACTH
sex differences: female advantage
verbal, perceptual speed and accuracy, fine motor skills
sex differences: male advantage
spatial, quantitative
Block and human figure: rotation task
block test: male advantage
human figure: magitude of sex differences on mental rotation tasks varies according to test content and item properties
—female performance WAY increased compared to block
—-males: performance improved from baseline when figures were male, didn’t increase when figures were female
radial arm maze: male advantage, reflects different strategy use
male rats tend to perform better on radial arm mazes compared to females
- WM: visit each arm only once (error: go down 1+ time)
- RF: go down only baited arms (error: down unbaited arm)
- male improved performance may be a reflection of strategy!
- use only geometry (extra visual cues), females use geometry AND landmarks (internal maze cues); may be males have less to learn so can learn faster
Estrogens on L and M
estrogen enhances WORKING MEMORY, but doesn’t impact or may even impair REFERENCE MEMORY
- enhances consolidation and acquisition in spatial memory tasks
- improves memory on tasks when the task is difficult
Luines delayed task
radial arm maze, 1 hour delay between arm 4-5 (more difficult task)–> memory of rats with estradiol injections improved
hippocampal circuity and estradiol
estradiol–> increased spine density in CA1 neurons–> increased neural connections–> enhanced memory
estradiol treatment, BIBN 99, NMDA receptor binding
estradiol treatment–> marked increase in NMDA receptor binding
- EVIDENCE
- –E–> increased NMDA binding
- –E+ BIBN–> blocked effect of E
- –BIBN alone: no effect
estradiol treatment, BIBN 99, WM performance
- E–> greeter number of correct until first error (improved performance)
- E+B–> effects of estrogen on performance BLOCKED
conclusion from studies with estradiol and BIBN 99
- estradiol acts on brain and cholinergic systems and behavior
- estradiol acts on cholinergic systems; cholinergic neurons bind to GLUTAMATE releasing neurons and exert a downstream effect
-by blocking estradiol, not allowing E to stimulate cholinergic pathway–> block effects of M2–> decreased spine density and dendritic length
Sherwin: changes in hormones during menstrual cycle associated with cognitive functioning
menopause: decrease in E, account for decline in cog functioning?
- E replacement within a critical period-> protection of cognitive functioning
