Lecture 4 Plasticity Flashcards
what is plasticity?
When the brain changes itself through thinking
The structure and function changes all the time through perception, task performance and after damage.
What is the consequence of plasticity?
When one area of cortex loses its function it takes up a new task.
What is cortical expansion?
The size of the represented body part depends on how much it is used.
What is plasticity in terms of synapses
- Strengthening, weakening, pruning
- Central governing rule, hebbian learning
- Synapses weaker if the activity of neurons are not correlated.
What is plasticity like in infants?
Non-selective, all stimuli induce plastic changes = critical period of development
What is plasticity like in adults?
Selective, controlled by task demands and context.
What stimuli induce plasticity?
Salient
What are salient stimuli?
Stimuli in focus of attention (in working memory)
Stimuli that is surprising
Stimuli that predicts reward
What drives plasticity?
Enhanced by neuromodulators released from limbic system
Areas of limbic system are activated in context and task dependent way.
What is an example of plasticity in rats?
When the neuron connecting whiskers is cut, other areas of the brain take up that cortical region.
What example of cortical reorganization is there?
Echolocation
- Recruits visual cortex
- Increased BOLD (bloodflow) activity in occipital and other area.
What did Elbert et al (1995) find about cortical expansion in the motor cortex?
Were looking at the distance of representation of the thumb and the little finger
String players vs controls
Found that controls representation was smaller than string players who have a larger representation of left hand.
But only found mainly in the left hand.
What is tonotopic mapping?
A spatial map of where sounds of different frequencies are processed in the brain
What did tonotopic mapping show?
That plasticity is reversible
Older rats auditory cortex tuned to a youthful state
What traditional methods were there for treating neurological impairment?
Pharmacological
Targeting behaviour
