Control of Visually Guided Eye Movements
The Classification of Eye Movements
The retina is specialized in having only a small
region of tightly packed photoreceptors called the fovea. This region
affords high-acuity vision. To be able to see fine detail in the visual
scene, we therefore have to repeatedly shift the direction of our gaze.
Two general classes of eye movements have been
distinguished: Conjugate eye movements and vergence eye movements. Conjugate
eye movements are of two types: saccadic and smooth pursuit.
The function of saccadic eye movements is
to rapidly acquire objects in the visual scene for central viewing
so that they may be analyzed in detail.
The function of the smooth pursuit system
is to maintain a moving object in central view as in the case of tracking
a bird in flight.
For the most part different neural mechanisms
control saccadic and smooth pursuit eye movements. Research in the Schiller
Lab is concerned predominantly with the neural control of visually guided
saccadic eye movements.