PSYC2020 Quiz 2: Slides 10 -15

Lateral inhabitation occurs when a receptor sends an excitatory signal to the brain. However, the lateral connections that connect our ganglion cells act as inhibitors. Every time a receptor is stimulated it sends an excitatory signal to the brain but also sends an inhibitory signal to the neighbouring receptor. The illusion occurs when a receptor (A) gets a strong excitatory signal from intense light (bright stimuli) but its neighbouring receptor (B) is getting a weak excitatory signal from dim light. Therefore (B) is getting a strong inhibitory signal from (A) but a weak inhibitory signal from its neighbouring receptor (C). The result is that we are able to distinguish edges in our environment.

Where does Lateral Inhabition occur?

Half the optic nerves leaving the eye cross over to the contralateral eye.

True. This process is called hemidecussation.

What is the purpose of hemidecussation?

Retinotopic organisation is when spatial relationships are preserved from the retina all the way back to the visual cortex.

What is the Cortical Magnification Factor ?

Rejoins that process information from the foveas are located laterally in your brain.

False. The areas dedicated to processing information from the foveas are located medially in the brain to protect the rejoin from potential damage.