Non-declarative memory Flashcards
Teacher: de Gee
Give the outline of nondeclarative memory.
Long term memory: nondeclarative memory: repeated presentations –> Habituation, sensitization, priming (skills and habits)
What is habituation?
The progressive decrease of the amplitude/frequency of a motor response to repeated sensory stimulation, withdrawal reflex becomes weaker
What makes the sea slug (aplysia) a good model to research habituation on?
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.
What is the neural basis for habituation?
The connection between sensory cell and motor neurons, specifically the chemical transmission between the cells
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
1) Because after habituation APs stay the same
3) This does not happen
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
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
What is homosynaptic habituation?
Only the synapses that have been fired during habituation will have a decreased firing rate –> stimulus specific
What is sensitization?
Repeated administration of a stimulus results in the progressive amplification of a response
What happens in the motor neuron respons when it is sensitized?
There is a bigger post synaptic potential, so an enhanced retraction
Which neuromodulator is released and so involved in sensitization?
Serotonin
What is the reaction pathway of sensitization?
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
What is heterosynaptic sensitization?
Because of the involvement of serotonin, more synapses get involved, which makes sensization stimulus unspecific (also an interneuron is involved)
What is priming?
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.
What is the difference between priming and recognition in context of depth?
- Priming involves shallow features
- Concious memory requieres deep processing
What is the difference between priming and recognition in context of duration?
- Priming: same one week later
- Conscious memory: mostly forgotten during first couple of days
In which areas are priming and conscious memory implemented?
- Priming: sensory cortex
- Conscious memory: hippocampus and higher order cortical regions (like frontal cortex)
What is the meaning of having skills?
The capacity to execute a motor/cognitive program
What are the characteristics of skills?
- Difficult to tell/transfer to others
- The content cannot be retrieved consciously
- Dependent on feedback during learning
- Repetitions are necessary to learn/stick
With what kind of task can percepual-motor skills be tested and what is measured?
Serial reaction time task: RT & accuracy
What do use see between controls and cerebellar lesion patients during a mirror drawing test?
The mean completion time of the patients remains longer than the control
What is the power law of learning?
The improvement in performance decreases exponentially as a function of the number of repititions
What are the 3 stages of skill learning?
- Cognitive –> what to do
- Associative –> how to do it
- Autonomous –> do it
What are important structures involved in skill learning?
- Dorsal striatum: caudate nucleus & puta.men
- (Pre-)motor cortex
- Cerebellum
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?
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
What can be concluded form the T-maze task?
When learning a skill, motor patterns are created in the brain
What is seen in the (pre-)motor cortex during skill learning?
Postsynapses will reach their threshold more easily over time –> number of active neurons first go up and then down but mutual coherence increases (summation)
