Subcortical Oculomotor Reflexes Flashcards
What do the receptive fields of the neurons in the superficial layers of the superior colliculus form?
A retinotopically coded map of the visual field
What is a movement field?
Part of the visual field to which the eyes move in response to activity in the cell
Where are neurons located that have movement fields?
In the deeper layers of the superior colliculus
What is a saccade?
A rapid eye movement
How are the motor layers of the superior colliculus organized?
The smallest saccades are represented in the rostral part, and the largest are in the caudal part
What capabilities do neurons in the deeper layers of the superior colliculus have?
Visuomotor or pure motor capabilities
What do neurons in the superficial layers of the superior colliculus receive info from?
The retinal ganglion cells
What are the cells in the superior colliculus ideal for?
Detecting the location of visual events and triggering orienting responses. It’s a survival mechanism!
The superior colliculus plays an important role in generating which kind of eye movement?
Reflexive eye movements
What is another name for reflexive eye movements?
Exogenous eye movements
What do fixation cells do and where are they located?
They keep your eyes from moving when you’re trying to fixate on something.
They’re located in the rostral superior colliculus
What is the fixation reflex?
Helps our eyes maintain their position by inhibiting activity of the saccade cells (and through them, eye movements)
What does the activation of saccade cells inhibit?
Fixation cells
What is the fixation offset effect (FOE)?
Reaction time on overlap trials minus reaction time on offset trials
Provides a measure of the responsiveness of the fixation reflex (large FOE = strong reflex)
Does fixation overlap or fixation offset lead to faster initiation of an eye movements?
Fixation offset
