Lecture 9 Flashcards
Explain time dependency for neural systems and there two periods.
If neural signals are not used then they will break done and became unavailable for use. There is a critical period where if the neural signals aren’t used in this period the function will be lost and there is a sensitive period where the function may still be apparent but it won’t be as good as it could have been
What two things is the maintenance and reorganisation of neural systems dependent upon?
- Time dependency
2. Experience/use
Explain experience/use in the maintenance and reorganisation of neural systems. What did hebb state?
If neural signals aren’t used then there synapses are weakened. As hebb says, “neurons that fire together, wire together”
Explain what the experiments on deprivation, enrichment and exercise find on both neural structures and behaviour.
Experiments found that when an animal is in an enriched environment and performing exercise they have more complex neural structures and are more aware of their environments then those who were deprived.
Where are the greater number of synapses and dendrite spines found?
In the dentate gyrus of the hippocampus and olfactory bulbs
What did hubel and wiesels study conclude? What does this support?
Hubel and wiesels study found that when you sutured shut an eye in a kitten, neural functioning of that eye was lost. But when a 12 month old cat had it’s eye sutured, there were no changes in ocular dominance but neural signal activity decreased overall. This supports the time dependency and use paradigms for neural system maintenance.
If you look at the layers of the primary visual cortex for a short deprived and long deprived cat, what would you find?
That there are no neural structure differences in the primary visual cortex between short and long deprivation of eye sight.
Explain competition in neural development both in terms of visual and motor processes.
Competition in neural development occurs when a function is reduced (e.g. Seeing from one eye) and the opposite function is increased. So neurons for extinct functions would decrease and neurons for opposite functions would increase. It’s a shift and rebalance of multiple processes.
Explain the effects of knudisens and brainless barn owl experiment on sensory cortex maps.
Knudisens and brainards experiment on barn owls found that when owls were fitted with vision altering eye prisms they struggled to locate prey visually and aurally. However, with practice they could locate the prey as the vision and auditory cortex maps shifted the corresponding amount to alter for real space differences.
In what layer of the primary visual cortex would you find the activation of neural signals ?
Layer IV. Or 4.
Where in the auditory system would the auditory map shift to accommodate changes?
The tectum
Explain the relationship between musicality and age.
The younger a person is exposed to and practices music the larger the cortical area would be for that function
Does plasticity occur in adults?
Yes, to a degree training can induce changes in the cortex to accommodate to new functions
What’s the phantom limb phenomena?
The phantom limb phenomena is when you can still “feel” sensations from the limb as though it occurs space.
What did ramachandran discover? Explain why this could happen?
When a patient who was missing their left arm after an accident had their cheek stroked they would report feeling in left arm. This could happen because sensations for hands and the faces are adjacently represented on the cortical map therefore the face region would occur more of the hand region now.
What is anterograde neural degeneration?
Forward disruption- When the neuron is destroyed from the point of disruption to the synaptic terminals.
