Vision

Question 1

What is lateral inhibition

Answer 1

Process by which neighbouring neurons in sensory system inhibit one another’s activity

Question 2

Explain lateral inhibition in the retina

Answer 2

When light falls on retina, it interacts with photoreceptor cells in center of visual field – centre cells

Surround cells receive indirect input from light through network of interconnected cells

When centre cells are stimulated by light they send inhibitory signals to surround cells which dampens their activity & thus reduces their response to light stimulus

This creates a contrast enhancement effect – center cells become more active than their surrounding cells leading to sharpening of edges & contours of visual stimulus

Crucial for visual perception as it allows us to distinguish fine details & detect boundaries between objects

Question 3

What are bipolar cells

Answer 3

Interposed between receptor & ganglion cells (connective neuron)

Question 4

What are amacrine & horizontal cells

Answer 4

Allow for integration at retinal level

Do a lot of processing within retina

Question 5

What are the 3 colours detected by cones in retina

Answer 5

3 colour cones are red, green & blue

Overlap gives shades in between