Visual Feature Tuning Properties of Short-Latency Stimulus-Driven Ocular Position Drift Responses during Gaze...

Area of Science:

• Neuroscience
• Ophthalmology
• Vision Science

Background:

• Ocular position drifts during gaze fixation are less understood than microsaccades.
• A recent study identified short-latency ocular position drift responses triggered by visual onsets.

Purpose of the Study:

• To systematically investigate feature tuning properties of ocular drift responses.
• To unravel the mechanistic substrates of ocular drift responses for neurophysiological experiments.

Main Methods:

• Precise eye tracking in three male rhesus macaque monkeys.
• Systematic testing of visual stimulus features including size, contrast, and location.

Main Results:

• Drift responses occur for tiny foveal stimuli and exhibit size tuning and monotonic contrast sensitivity.
• Peripheral visual targets induce spatially directed drift modulations.
• Drift responses are synchronized with stimulus-induced saccadic inhibition and suppressed by peristimulus saccades.

Conclusions:

• Ocular drift responses are feature-tuned and influenced by stimulus size, contrast, and location.
• These responses are linked to rapid visual neural activity impacting oculomotor control.
• Further research is needed to fully understand the neurophysiological basis of ocular drifts.