Non-declarative memory

Question 1

Give the outline of nondeclarative memory.

Answer 1

Long term memory: nondeclarative memory: repeated presentations –> Habituation, sensitization, priming (skills and habits)

Question 2

What is habituation?

Answer 2

The progressive decrease of the amplitude/frequency of a motor response to repeated sensory stimulation, withdrawal reflex becomes weaker

Question 3

What makes the sea slug (aplysia) a good model to research habituation on?

Answer 3

They have a gill withdrawal reflex, which reduces when the siphon is being touched multiple times
+ Their brain is hard wired, which means that every sea slug has the same set of neurons making it easier to study.

Question 4

What is the neural basis for habituation?

Answer 4

The connection between sensory cell and motor neurons, specifically the chemical transmission between the cells

Question 5

Which potential mechanisms behind habituation are INcorrect and why?
1. S action potentials reduce after repeated firing
2. S glutamate smaller excretion
3. M# receptors reduced
4. S & M # synapses reduced

Answer 5

1) Because after habituation APs stay the same
3) This does not happen

Question 6

Which potential mechanisms behind habituation are CORRECT and why?
1. S action potentials reduce after repeated firing
2. S glutamate smaller excretion
3. M# receptors reduced
4. S & M # synapses reduced

Answer 6

2) In a habituated synaps, less glutamate is docked to the active side, so less Glu will be released, so post synaptic potential is smaller
4) Does happen but only after long term habituation

Question 7

What is homosynaptic habituation?

Answer 7

Only the synapses that have been fired during habituation will have a decreased firing rate –> stimulus specific

Question 8

What is sensitization?

Answer 8

Repeated administration of a stimulus results in the progressive amplification of a response

Question 9

What happens in the motor neuron respons when it is sensitized?

Answer 9

There is a bigger post synaptic potential, so an enhanced retraction

Question 10

Which neuromodulator is released and so involved in sensitization?

Answer 10

Serotonin

Question 11

What is the reaction pathway of sensitization?

Answer 11

A interneuron secretes serotonin onto a serotonin receptor on a presynaps of the sensory neuron –> serotonin receptor gets activated –> G proeitn becomes activated causing ATP to release –> ATP + adenylcyclase becomes cAMP –> cAMP phosphorylates PKA subunits –> catalytic subunit causes more K+ efflux –> longer repolarization happening —> voltage-gated Ca2+ stays longer open –>more vesicles are docked –> more Glu release –> sensitzation

Question 12

What is heterosynaptic sensitization?

Answer 12

Because of the involvement of serotonin, more synapses get involved, which makes sensization stimulus unspecific (also an interneuron is involved)

Question 13

What is priming?

Answer 13

A nonconscious form of memory that involves a change in a persons ability to identify, produce or classify an item as a result of a previous encounter with that item or a related item.

Question 14

What is the difference between priming and recognition in context of depth?

Answer 14

• Priming involves shallow features
• Concious memory requieres deep processing

Question 15

What is the difference between priming and recognition in context of duration?

Answer 15

• Priming: same one week later
• Conscious memory: mostly forgotten during first couple of days

Question 16

In which areas are priming and conscious memory implemented?

Answer 16

• Priming: sensory cortex
• Conscious memory: hippocampus and higher order cortical regions (like frontal cortex)

Question 17

What is the meaning of having skills?

Answer 17

The capacity to execute a motor/cognitive program

Question 18

What are the characteristics of skills?

Answer 18

• Difficult to tell/transfer to others
• The content cannot be retrieved consciously
• Dependent on feedback during learning
• Repetitions are necessary to learn/stick

Question 19

With what kind of task can percepual-motor skills be tested and what is measured?

Answer 19

Serial reaction time task: RT & accuracy

Question 20

What do use see between controls and cerebellar lesion patients during a mirror drawing test?

Answer 20

The mean completion time of the patients remains longer than the control

Question 21

What is the power law of learning?

Answer 21

The improvement in performance decreases exponentially as a function of the number of repititions

Question 22

What are the 3 stages of skill learning?

Answer 22

• Cognitive –> what to do
• Associative –> how to do it
• Autonomous –> do it

Question 23

What are important structures involved in skill learning?

Answer 23

• Dorsal striatum: caudate nucleus & puta.men
• (Pre-)motor cortex
• Cerebellum

Question 24

What is seen in a mice experiment with a T-maze where they have to listen to frequency to go the right way for a reward?

Answer 24

More correctness and faster running time was seen during the learning stage.
- In the beginning the striatum hard wires a motor program to excecute the task right away.
- At the end only intitiation of the motor program was needed to excecute the task and after finding reward, the motor program is being terminated

Question 25

What can be concluded form the T-maze task?

Answer 25

When learning a skill, motor patterns are created in the brain

Question 26

What is seen in the (pre-)motor cortex during skill learning?

Answer 26

Postsynapses will reach their threshold more easily over time –> number of active neurons first go up and then down but mutual coherence increases (summation)