Learning and memory

Question 1

Importance

Answer 1

• Sense of self
• Survival: detecting threats
• Learn predictive value of signals
• Understand when it goes wrong
• Understand how behaviour is shaped by experience

Question 2

Learning and memory

Answer 2

-The acquisition and retention of change in behaviour

Question 3

Behaviour

Answer 3

-Acquired and maintained by synaptic plasticity, conditioning, perceptual and relational learning.

Question 4

Synaptic plasticity

Answer 4

• Ability to learn and regenerate lost skills

- Synapses strengthen or weaken over time due to increase or decrease in activity

Question 5

Hebbs rule

Answer 5

-If a synapse is repeatedly activated the structure or chemistry will change and become strengthened

Question 6

Hebb rule evidence

Answer 6

• Bursts of 100 electrical pulses were sent through a pathway to the hippocampus. then a single pulse was delivered later which showed an increased response in the structure at the end of the pathway
• Blink neuron was activated by a puff of air to the eye paired with a music note. This strengthened the connection between the neurons so the music note on its own would cause blinking

Question 7

Location of plasticity

Answer 7

-Hippocampal formation is the major area for learning and memories

Question 8

Long term potentiation

Answer 8

• Strong activity releases glutamate which activates NMDA receptors which release calcium which strengthens connections
• seizures, anorexia or hypoglycemia cause abnormally high levels of glutamate which causes an influx of calcium which can be toxic and destroy neurons

Question 9

Long term depression

Answer 9

-AMPA receptors are removed which reduces the connections and efficiency of the synapse

Question 10

Perceptual learning

Answer 10

-Subconscious ability to learn to recognize new stimuli or changes/variations of new stimuli

Question 11

Learning to recognise stimuli

Answer 11

-Synaptic connections in the visual association cortex change to create new neural circuits for recognition e.g. when the visual association cortex was stimulated, memories/images were recalled

Question 12

Learning to respond to stimuli after a short delay

Answer 12

-If you see someone walk into a room, and you look away you know they are still there due to continued activity in the neural circuits in the fusiform face area of the visual association cortex (perceptual short term memory)

Question 13

Classical conditioning leads to learning

Answer 13

-Conditioning can create emotional responses e.g. little albert.

Question 14

Neural processes of classical conditioning

Answer 14

• A loud noise activates synapses in the lateral nucleus, which activates the central nucleus creating a fear response
• If this is paired with an unconditioned stimulus the connection is strengthened causing the synapses to fire together as the AMPA receptors between the synapses in the lateral amygdala and the axons that cause the conditioned fear are strengthened which creates a conditioned response

Question 15

Instrumental conditioning (operant conditioning)

Answer 15

• Allows us to profit from experience e.g. if we make a response that has a favorable outcome, then it is likely going to be repeated.
• The actions associated with instrumental conditioning begin in the sensory association cortex and end in the motor association cortex of the frontal lobe.

Question 16

Transcortical pathways between sensory and motor association cortex

Answer 16

• Involved in the acquisition of complex behaviors relevant to deliberation and instruction (memorized set of rules/script) e.g. learning to drive
• All consuming process, requiring explicit concentration and effort

Question 17

Basal ganglia and thalamic pathways

Answer 17

-Over time actions become rehearsed (habitual), at which time the basal ganglia and thalamus table over the process subconsciously allowing us to use the transcortical pathway to learn new things.

Question 18

Action of reinforcement

Answer 18

• There are several reinforcement mechanisms in the brain including the dopamine system e.g. mesolimbic and mesocortical dopaminergic systems
• The medial forebrain bundle connects the ventral tegmental area if either is stimulated (by reward or drugs) dopamine is released from the nucleus accumbens

Question 19

Factors that impact reinforcement

Answer 19

• Motivating operation: stimuli may work as a reinforcer on one occasion but not another (hungry bs sated).
• Unexpected vs expected: Berns et al (2001) found that an unexpected squirt of juice activated the nucleus accumbens, but that predictable delivery did not. VAT dopaminergic neurons signal to other areas of the brain that something must be learnt. If the reward was predicted nothing needed to be learnt.

Question 20

Most memories are connected

Answer 20

• Most episodic memories of real objects and events are related to other memories
• When you see a friend, you remember how to say their name, and the memories shared with them which lead to the reactivation of a specific series of events

Question 21

Relational learning

Answer 21

• The neural circuits in the visual association are connected to circuits in many other parts of the brain, and these are connected to many others.
• Includes the establishment and retrieval of memories of events, episodes and places

Question 22

Anterograde amnesia

Answer 22

-In its simplest form is the inability to learn new information

Question 23

Anterograde amnesia pure

Answer 23

-Able to remember past events from before the brain damage but cannot remember any information learnt after. Very rare, often occurs with retrograde amnesia.

Question 24

Pure retrograde amnesia pure

Answer 24

-Inability to remember events that happened before the brain damage occurred

Question 25

Cause of anterograde amnesia

Answer 25

• Korsakoff’s amnesia (Destruction of the mammillary bodies - chronic alcoholism)
• HM: Damage to the temporal lobes e.g. surgery to relieve epileptic seizures

Question 26

HM

Answer 26

-Initially thought that he was unable to convert STM to LTM but now it is believed that perceptual learning, classical conditioning and motor learning are still intact

Question 27

Evidence conditioning is intact

Answer 27

-Psychiatrist hid pin in hand and shook his amnesia patients’ hand, negative association with shaking his hand must have been learnt as the next time they met the patient didn’t want to shake his hand

Question 28

Declarative memories

Answer 28

-Explicit memory: conscious recollection of facts, events or specific stimuli

Question 29

Non-declarative memories

Answer 29

-Implicit memories: perceptual learning, classical conditioning and motor learning

Question 30

Hippocampus problems

Answer 30

-Gradually transforms declarative memories to permanent storage

Question 31

preventing classical conditioning

Answer 31

-ZIP drug prevents protein synthesis necessary for LTP

Question 32

LTP neural process

Answer 32

• LTM is associated with the hippocampus (storage and retrieval).
• Action potential for learning passes through the dentate gyrus then the CA3 and CA1 region
• Repeated activation of CA3 and CA1 region results in LTP (long lasting signal transmission enhancement)
• Action potential causes glutamate to be released which binds to the NMDA and AMPA receptors. If the action potential is strong enough a large influc of sodium will enter the NMDA receptor which causes magnesium to be repelled from the AMPA receptor. This allows calcium to enter the post synaptic neurone.
• AMPA receptors are coincidence detectors as the require a pre and post synaptic event

Question 33

Early and late phase of LTP

Answer 33

• Early phase = calcium attaches to binding site which produces more AMPA receptors at the post synapse
• Late phase = prolonged influx of calcium produces more transcription factors which changes genes and causes protein synthesis which produces growth factors which create more synapses (synaptic plasticity) between CA1 and CA3 neurones
• Effects can last for just a few hours or a life time depending on activity