Behavioral Neuro Test 3

Question 1

Pavlovian Learning

Answer 1

CS=Sound, US=blow of air, CR=blink

Question 2

Hebbian Learning

Answer 2

if presynapse becomes active at same time as postsynaptic neuron(repeatedly), relationship will be strengthened between the two.

“neurons that fire together wire together”

Question 3

Engram

Answer 3

biological substrate of memory
anything that has been biologically changed (strengthened synapse)

Question 4

Karl Lashley

Answer 4

most of his work is wrong, but we can learn from it.
- believed size of deficit in rat brain corresponded to size of cortical lesion (used maze running to test this) – bigger lesion= worse off
- concluded that engram was diffuse (stored across the brain) and intact brain regions can compensate for damage (equipotential)

Question 5

How was Karl Lashley’s work wrong

Answer 5

• equipotentially- believed that all parts of cortex contribute equally to complex behaviors and all any part of cortex can substitute (this is not true lol)
• needed to look at more than 1 task- doesn’t represent all learning types
• mass action- cortex works as a whole, more cortex= better. This was wrong.
• his task was too complex
• cerebral cortex isn’t the only place to look for engram

Question 6

Modern day search for engram

Answer 6

Task used: eyeblinking
Location: engram found in cerebellum (lateral interpostitus nucleus)
Method: pavlovian conditioning. used muscimol to shut down areas of the brain.

Question 7

a->b->c->d->e->f

Answer 7

you need ALL parts of the process for learning to occur

Question 8

eyeblink conditioning in humans

Answer 8

PET Scans- developing eyeblink conditioning response is associated with increased activity in cerebellum and red nucleus
Cerellar damage= weaker conditioned eyeblings, and blinks are less accurately timed relative to onset of air puff

Question 9

HM- who was he, why do we care

Answer 9

had epilespy. doctors found out medial temporal lobe was where the issue was, so they removed it. seizures went away but now had memory issues.

Question 10

intact areas HM

Answer 10

reterograde memory
immediate memory
IQ
vision
logic/reasoning
language
motor control

Question 11

impaired things HM

Answer 11

anterograde amnesia
retrieving recent memories pre operation ( a little retrograde amnesia)

Question 12

retrograde amnesia

Answer 12

cannot remember events prior to damage. Temporally graded, function of consolidation, only episodic memories only are impaired

Question 13

temporally graded meaning

Answer 13

recent memories impacted, older aren’t as much. called ribots law

Question 14

episodic memories

Answer 14

memories unique to your experience

Question 15

semantic memory

Answer 15

vocab or facts

Question 16

Patient EP

Answer 16

also had MTL damage(but it was due to injury).

Question 17

Patient EP vs patient HM (what was wrong with the brain)

Answer 17

HM: Bilateral MTL lobectomy to treat epilepsy
EP: viral encephalitis damaged the brain

Question 18

Why do we care about HM and EP?

Answer 18

demonstrates that certain brain areas can be tied to particular memory functions. Memory isn’t diffusely or equivalently spread throughout the whole brain as Lashley thought.

Also demonstrates that there are different modes of storage for short term vs long term memory vs remote memory. this led to the concept of memory consolidation (ST to LT memory conversion)

Demonstrates there are multiple memory systems in the brain

HM had damage to declarative/explicit memory system, but he also had damage to the area around it. (the entire medial temporal lobe and amygdala)

Question 19

medial temporal lobe consists of

Answer 19

hippocampus and parahippocampal gyrus (entorhinal perirhinal, parahippocampal(aka postrhinal in rats))

Question 20

medial temporal cortex consists of what

Answer 20

parahippocampal gyrus (entorhinal, perirhinal, parahippocampal)

Question 21

name for parahippocampal in rats

Answer 21

postrhinal

Question 22

declarative/explicit memory

Answer 22

recall and recognition

Question 23

Monkey Experiment for memory

Answer 23

Method: give monkey object and underneath it is food. Then cover animal’s view of the object(I.e. lowering a screen. When the screen is opened, give them the same object (no longer food under it) and a different object (w new food)
Results: does monkey know they ate the old food? Monkeys with MTL lesions had major decrease in object recognition.
The longer the delay period was, the worse memory was.

Question 24

location of hippocampus (rodents vs monkey)

Answer 24

rodents: more dorsal
monkey: more ventral

Question 25

rat experiment and memory

Answer 25

similar to the monkey experiment, but there are doors in a box with objects.
results: only a decrease in performance when medial temporal cortex was lesioned (NO difference when hippocampus and amygdala were lesioned)
this shows that the hippocampus isn’t critical for object recognition.

Question 26

what is the hippocampus needed for

Answer 26

spatial and contextual memory

Question 27

tests for spatial memory

Answer 27

• morris water maze
• radial arm maze
• T maze or plus maze
• place cells

Question 28

place cells

Answer 28

neurons that respond only when subject is in specific locations

Question 29

repetition priming tests

Answer 29

dont need to have explicit memory of actually learning
* stem completion test
* incomplete pictures
* mirror tracing task
* skeletal conditioning
* emotional conditioning

Question 30

stem completion test

Answer 30

have participants read a list of words and then have a ‘delay period’ (aka distract them)

Then give them the stem (beginning) of a word and have them finish the word
results: more likely to fill in the word that they say even if they didn’t remember ever doing the initial task)

Question 31

incomplete picture task

Answer 31

same as stem completion but with incomplete pictures instead. For example, after many trials HM ‘guessed’ the object very quickly but he doesn’t remember doing the trial before.

Question 32

mirror tracing task

Answer 32

targets implicit memory in motor skills. trace an object by looking at your reflection in a mirror. HM improved in this task over time even though he didn’t remember doing it

Question 33

skeletal conditioning example

Answer 33

eyeblink pavlovian

Question 34

emotional conditioning example

Answer 34

fear pavlovian

Question 35

declarative memory areas

Answer 35

medial temporal lobe- hippocampus and MTC

Question 36

repetition priming areas

Answer 36

semantic (meaning)=frontal lobe
modality(visual)=visual cortex

Question 37

motor skill learning areas

Answer 37

basal ganglia (dorsal stratum=caudate+putamen)

Question 38

skeletal conditioning for eyeblink area

Answer 38

cerebellum

Question 39

emotional conditioning for fear area

Answer 39

amygdala

Question 40

place vs response

Answer 40

place=spatial skills, response=muscle memory

Question 41

Place and response study

Answer 41

used a plus maze and moved where the rat started. this shows place vs response learning.

Found that animals with inactivated caudate showed place learning and those with inactiviated hippocampus relied on response learning. place vs response was mediated by different neural systems- this was evidence that multiple memory systems function independently.

Place learning (hippocampus) is acquired faster than response learning (caudate).
Learning occurs concurrently. One does not get ‘erased’ from the brain, it is always in tact but one might just take over. Time can also influence which one is used.

Question 42

LTP- what it stands for, where it is, what it is usually suggested to underly.

Answer 42

long term potentiation. It is usually studied in the hippocampus but there is also evidence of LTP in amygdala. It is like the engram but is usually suggested to underly auditory fear conditioning (I.e. tone and shock).

Question 43

LTP key properties

Answer 43

1. can last for a long time. for several months to a year after multiple high frequency stimulations
2. many forms can develop only If there is a co-occurrance of activity in presynaptic and postsynaptic cells.

Question 44

NMDA receptor

Answer 44

receptor for glutamate(main excitatory neurotransmitter in the brain)

Question 45

for NMDA to respond maximally

Answer 45

glutamate must bind and postsynaptic neuron must already be partially depolarized. influx of calcium ions that triggers events that induce LTP