Gain control Flashcards
1
Q
What is gain control?
A
Mechanism for neurons to control their sensitivity
2
Q
Why is gain control needed?
A
As neurons have to code for large dynamic ranges
3
Q
What is contrast?
A
The average luminance variation in part of the visual field
4
Q
How does contrast model gain control?
A
neuronal inputs are divided by the sum of the local average response
5
Q
What are the 4 signatures of cortical gain control?
A
- Operates over a long range
- Tuning
- Slow
- Complex features
6
Q
What is the dipper function?
A
Graph of experiment carried out by Nachmias and Sansbury which finds a ‘dip’ at which the visual system is at its most sensitive
7
Q
Where has abnormal gain control been observed?
A
Autism, schizophrenia, epilepsy and Parkinson’s
