Spatiotemporal structure of visual receptive fields in macaque superior colliculus

Area of Science:

• Neuroscience
• Oculomotor Research
• Visual Processing

Background:

• The superior colliculus (SC) is crucial for selecting visual targets for saccades.
• While its role in eye movement control is known, visual response characteristics in the SC are less understood.

Purpose of the Study:

• To characterize the spatiotemporal structure of visual receptive fields in the macaque SC.
• To investigate how SC visual responses influence saccade timing and how saccades affect visual processing within the SC.

Main Methods:

• Recorded neuronal activity in the intermediate layers of the macaque SC.
• Utilized a sparse-noise mapping procedure to map visual receptive fields.
• Analyzed responses to flashed visual stimuli and their relationship to saccade execution.

Main Results:

• SC visual responses commence ~50 ms post-stimulus onset and persist for ~70 ms.
• Approximately 50% of SC neurons exhibit suppression by stimuli in flanking receptive field locations, influencing saccade timing.
• Saccades modulate SC visual processing, similar to saccadic suppression/enhancement in the cortex, but with inverse correlations between sensitivity and firing rates.

Conclusions:

• SC receptive field processing influences oculomotor behavior.
• Oculomotor signals from the SC shape perisaccadic visual perception.
• SC neuronal activity plays a key role in filtering distractors and guiding visual attention during saccadic eye movements.