Learning and Memory (Lecture 9)

Question 1

learning=

Answer 1

acquiring new knowledge, behaviors, or skills

Question 2

explicit memories

Answer 2

declarative, things you can describe

Question 3

implicit memories

Answer 3

non-declaractive, things learned through experience

Question 4

explicit: episodic memories

Answer 4

events

Question 5

explicit: semantic

Answer 5

facts

Question 6

short-term memory

Answer 6

minutes to hours

what did you have for dinner last night?

Question 7

long-term memory

Answer 7

relatively permanent (not forgotten)
(what did you do after high school graduation?)

Question 8

working memory

Answer 8

temporary storgage with limited capacity which requires rehearsal
(what’s your number?)

Question 9

engram (or memory trace)

Answer 9

physical representation or location of a memory

Question 10

Karl Lashley

Answer 10

examined the effects of brain lesions on performing a maze task
important contribution: memories are distributed

Question 11

severity of deficits caused by lesions correlated with _____ of lesion… not _____.

Answer 11

size… not location

Question 12

Donald Hebb

Answer 12

memories are stored in widely-distributed cell assemblies. these cell assemblies may involve many neurons (100-1000s) that are linked by synapses strengthened whenever activated together (i.e. learning)

Question 13

Hebb’s theory

Answer 13

if an engram is based on input from only one sensory modality, it should be possible to localize it within cortex devoted to that sense

Question 14

Wilder Penfield

Answer 14

canadian neurosurgeon “Montreal procedure”, electrical stimulation of the temporal lobe occasionally produced auditory hallucinations or recollections of past experiences (similar phenomenon during seizures of the temporal lobe)

Question 15

H.M. (Henry Gustav Molaison)

Answer 15

underwent medial temporal lobectomy (including most underlying hippocampus) to control seizure disorder, seizures stopped but partial retrograde amnesia and extreme anterograde amnesia

Question 16

what we can learn from the H.M. case:

Answer 16

1. medial temporal lobes are involved in memory
2. short-term and long-term memory are mediated by different brain structures
3. declarative and procedural memory are mediated by different brain structures
4. memory may exist but not consciously recalled

Question 17

delayed non-matching to sample study:

Answer 17

tests recognition memory. monkeys must displace NEW object to uncover food. as delays increased, lesioned animals showed worse performance

Question 18

what we can learn from delayed non-matching to sample:

Answer 18

medial temporal lobe structures important for forming (consolidating) declarative memories!

Question 19

______ cortex is integral in object recognition

Answer 19

rhinal

Question 20

bilateral removal of the RHINAL CORTEX results in:

Answer 20

object-recognition deficits

Question 21

bilateral removal of the HIPPOCAMPUS results in:

Answer 21

no or moderate effects on object recognition

Question 22

bilateral removal of the AMYGDALA has:

Answer 22

no effect on object recognition

Question 23

Morris Water Maze goal:

Answer 23

to test the hippocampus importance in spatial memory, (rats swim the maze searching for a hidden platform and after learning where the platform is, they swim straight there)

Question 24

in the Morris Water Maze: rats with bilateral hippocampal damage:

Answer 24

do not learn or remember location of platform

Question 25

long-term potentiation (LTP)=

Answer 25

long-lasting enhancement in signal transmission between two neurons that results from stimulating them synchronously

Question 26

neurons that repeatedly fire together become associated by:

Answer 26

LTP (Long-term potentiation)

Question 27

cellular mechanisms of learning and memory:

Answer 27

NMDA Glutamate receptors

• Ca2+ only enters cell when depolarization removes Mg2+ plug
• so, Ca2+ can only enter postsynaptic cell when it is already depolarized and receiving input from presynaptic cell

Question 28

rise in postsynaptic Ca2+ linked to:

Answer 28

LTP (Long-term potentiation)

Question 29

block Ca2+ influx=

Answer 29

block LTP

Question 30

rise in Ca2+ activates:

Answer 30

kinases (enzymes that can activate proteins within the cell)

Question 31

kinases increase LTP by:

Answer 31

1. increasing activity (ion conductance) of glutamate AMPA receptors
2. insertion of new AMPA receptors into membrane
3. development of new connections with presynaptic neuron

Question 32

LTP requires ____ receptors

Answer 32

NMDA

Question 33

when NMDA receptor blockers injected into hippocampus:

Answer 33

animals fail at water maze

Question 34

when there was a genetically increase in the number of hippocampal NMDA receptors:

Answer 34

animals show enhanced learning