Psyc 211 Learning And Memory

Front 1

define learning

Back 1

Learning refers to the process by which experiences change our nervous system.

Front 2

define memory

Back 2

Memory refers to the process that encodes, stores and retrieves the learning experience.
memories:
- can be transient or durable.
- can be consciously (explicitly) declared or involve implicit procedures.
- have a personal frame of reference
- permits a form of time-travel
- are not equally vulnerable to disease and disruption

Front 3

Associative learning

Back 3

In associative learning, the experimenter arranges a relationship between two events.

This type of learning involves connections between circuits involved in perception and those involved in movement.
- The resulting behaviour can be a reflexive response (e.g. salivation or eyeblink) or a complicated sequence of previously learned movements.
- Two major categories of associative learning:
- Classical conditioning
- Instrumental conditioning

Front 4

Differentiate between reflex neurons and those being learnt

Back 4

reflex ones have strong synapses and strong action potentials to make nerve fire so action happens. non reflexive ones must be learned and strengthened. for ex, if we puff air at eye, it blinks b/c the motor neuron has strong synapse with the somatosensory one, but if we play a sound, without classical conditioning the eye wont blink because the connection between the motor neuron and the auditory one is very weak.

Front 5

The Hebb Rule

Back 5

the cellular basis of learning involves the strengthening of a synapse that is repeatedly active when the postsynaptic neuron fires

Front 6

describe the neural circuits of instrumental conditioning/ reinforcement

Back 6

The process of reinforcement strengthens a connection between neural circuits involved in perception (sight of the lever) and those involved and those involved in movement (the act of lever pressing).

Front 7

perceptual learning; motor learning

Back 7

- the ability to learn to recognise stimuli that have been seen before.
-involves learning to make a new response. It cannot occur without sensory guidance from the environment.

Front 8

learning involves...

Back 8

perceptual, associative and motor components!
stimulus---> changes in neural circuits detects it (perceptual) ---> S-R learning (association) ----> changes in neural circuit controls behaviour (motor)

Front 9

Rational learning- spatial learning and episodic learning

Back 9

rational=Learning about the relationships among different stimuli
spatial=allows us to learn about relations among stimuli located in space.
episodic= enables us to remember sequences of events (episodes) that we witness

Front 10

synaptic plasticity; where shows much plasticity?; how is this plasticity manifested?

Back 10

changes in the structure or biochemistry of synapses that alter their effects on postsynaptic neurons; hippocampus; This plasticity is manifested through the phenomenon of long-term potentiation (LTP).

Front 11

Hippocampal Formation- parts, location

Back 11

The hippocampal formation is a collection of structures which include the hippocampus (CA1-CA4 fields), the dentate gyrus and the subicular complex; located in the temporal lobe.

Front 12

describe the workings of the hippocampus

Back 12

-The entorhinal cortex channels the major neocortical inputs and outputs.
-Granule cells of the dentate gyrus receive information from the entorhinal cortex via the perforant path.
-Neurons of the dentate gyrus send axons to the CA3 field and form synapses with dendrites of pyramidal cells.
--One branch of the axons of CA3 pyramidal cells travel through the fornix to reach areas of the basal forebrain.
--Another branch of axons synapse with the pyramidal cells of the CA1 field.
- CA1 pyramidal cells provide the main output of the hippocampus to the subiculum, entorhinal cortex and basal forebrain.

Front 13

How do we induce LTP?

Back 13

- A stimulating electrode is placed among the axons in the perforant path.
- A recording electrode is placed near the granule cells of the dentate gyrus.
- The size of the ‘first’ population EPSP (extracellular measurement of the EPSP) indicates the synaptic strength ‘before’ LTP has taken place.

- We can induce LTP if we stimulate the perforant path with high intensity, high frequency stimulation.
- A single pulse of electrical stimulation is delivered to the perforant path.
- This produces a population EPSP which is recorded in the dentate gyrus.

Front 14

Long Term Depression (LDT)- definition, when occurs, plays a role in

Back 14

- a weakening of the synaptic strength
- It occurs following slow rate of low-frequency stimulation ( he slow rate unlike the rapid rate of LTP, fails to depolarize the membrane) of the synaptic inputs to a cell.
- LTD also play an important role in learning and memory; some memory circuits are established by strengthening some synapses while weakening others

Front 15

What role does NMDA receptors play in LTP?

Back 15

NMDA receptors in the CA1 field of the hippocampus control calcium ion channels that are normally blocked by magnesium m2+. Drugs like AP5 that block NMDA receptors prevent calcium entering the dendritic spines and block LTP



If weak synapses
are active by themselves, nothing happens because
the membrane of the dendritic spine does not depolarize
sufficiently for the calcium channels controlled by the
NMDA receptors to open. (Remember that, for these
channels to open, the postsynaptic membrane must first
depolarize and displace the magnesium ions that normally block them.) However, if the activity of strong synapses located elsewhere on the postsynaptic cell has
caused the cell to fire, then a dendritic spike will depolarize the postsynaptic membrane enough to eject the magnesium ions from the calcium channels of the NMDA receptors in the dendritic spines. If some weak synapses become active right then, calcium will enter the dendritic spines and cause the synapses to become strengthened.

Front 16

What role does AMPA receptors play

Back 16

synaptic strength during LTP is due to AMPA receptors in CA1 field (ON DENDRITIC SPINE) which control Na+ channels. They are located at the base of the dendritic spines. When LTP is induced, the AMPA receptors flood into the CA1 neurons. This movement of AMPA is caused by a calcium dependent enzyme, CaM-KII. so, the more calcium there is (from the nmda) the more ampa receptors will move to spine and strengthen neuron.

Front 17

Describe the process of LTP

Back 17

- Terminal button releases glutamate which binds to the NMDA receptor
- Ca2+ (calcium ions) enter postsynaptic cell if membrane is depolarised (via NMDA receptors)
- Ca2+ activate CAM-KII
- CAM-KII facilitates the insertion of AMPA receptors into postsynaptic density
- LTP causes structural changes (e.g., dendritic growth)
- Long lasting LTP requires protein synthesis

Front 18

what does NMDA stand for

Back 18

N-methy-D-aspartate

Front 19

Wy is CaM-KII special?

Back 19

- CaM-KII can autophosphorylate; it can attach a phosphate group to a particular location on the molecule. This allows CaM-KII to remain active by itself without the need for calcium.

Front 20

Associative Long Term Potentiation vs non-associative

Back 20

A long-term potentiation in which concurrent stimulation of weak and strong synapses to a given neuron strengthens the weak ones.

-High-frequency stimulation of the axons in the circuit of neurons passes from the entorhinal cortex through the
hippocampal formation, strengthens synapses; it leads
to an increase in the size of the EPSPs in the dendritic
spines of the postsynaptic neurons

Front 21

Role of Lateral Nucleus of the amygdala in conditioning

Back 21

Info about the US (foot shock) and CS (tone) converge in the lateral nucleus. Interrupting LTP in lateral nucleus prevents establishment of a conditioned emotional response

Front 22

short term memory involves filtering what? this is done where?

Back 22

Filtering out irrelevant info and keeping relevant info- done in basil ganglia and right prefrontal cortex respectively

Front 23

As learned behaviours become automatic and routine, they are controlled by the:

Back 23

basil ganglia

Front 24

Basal Ganglia and learning

Back 24

involved in instrumental conditioning; lesions of it affect instrumental learning but not other forms of learning

Front 25

The Ventral Tegmental Area

Back 25

A group of dopaminergic neurons in the ventral midbrain whose axons form the mesolimbic and mesocortical systems; plays a critical role in reinforcement.

Front 26

Nigrostriatal pathway involved in____, mesocortical pathway____, mesolimbic pathway_____

Back 26

movement; motivation, cognition, emotion; reward and desire

Front 27

Medial forebrain bundle, if you administer cocaine/ electrically stimulate it?

Back 27

carries info from VTA to the nucleus accumbens thus plays role in reward; this causes dopamine release in the nucleus accumbens

Front 28

Prefrontal cortex role in reinforcement

Back 28

secreted glutamate which causes VTA neurons to burst fire which results in increase of dopamine release in the nucleus accumbens. sort of controls reinforcement when notices animal is headed towards its goal

Front 29

anterograde amnesia vs retrograde amnesia

Back 29

inability to learn new info caused by damage to hippocampal formation or regions that supply its inputs; inability to remember events before the incident

Front 30

H.M

Back 30

- had seizures, so had his bilateral medial temporal lobe removed
- surgery also removed some hippocampus and entorhinal cortex
- left with anterograde amnesia
- had poor spatial memories, couldnt remember names
- BUT priming facilitated his memory, and he showed associative and motor learning capabilities!

Front 31

declarative memories vs nondeclarative memories

Back 31

explicit, consciously learned, or previous experience; implicit, unconscious, like riding a bike or tying a shoe

Front 32

Anoxia

Back 32

when brain oxygen supply cut off- cuases damage to the CA1 which causes severe anterograde amnesia

Front 33

Semantic Dementia

Back 33

progressive neurodegenerative disorder characterized by a loss of semantic memories due to degeneration if anterior temporal lobe. usually have trouble finding words, aphasia, and matching pictures to words

Front 34

Korsakoff Syndrome

Back 34

anterograde amnesia caused by severe alcoholism
- confabulate -describe fictitious events they believe to be true

Front 35

Place Cells

Back 35

neurons in hippocampus with different receptive fields depending on where the animal is

Front 36

memory consolidation

Back 36

hippocampus deals with memories for 30 days then other regions take over