Peri-Saccadic Orientation Identification Performance and Visual Neural Sensitivity Are Higher in the Upper Visual...

Area of Science:

• Neuroscience
• Visual Perception
• Oculomotor Behavior

Background:

• Visual processing involves diverse brain areas with specialized functions and spatial anisotropies.
• The superior colliculus (SC) and primary visual cortex (V1) show different upper/lower visual field response patterns.
• Understanding perceptual performance during active vision requires examining these spatial anisotropies.

Purpose of the Study:

• To investigate whether peri-saccadic orientation identification performance is biased by visual or oculomotor spatial anisotropies.
• To compare human performance with neural responses in monkeys during peri-saccadic periods.

Main Methods:

• Human participants (n=48) identified orientations of stimuli presented in the upper vs. lower visual fields around saccades.
• Recorded peri-saccadic neural responses in the SC of two macaque monkeys.
• Compared performance during active saccades versus steady-state fixation.

Main Results:

• Humans identified upper visual field stimuli significantly better than lower visual field stimuli during peri-saccadic periods.
• This upper visual field advantage contrasted with steady-state fixation performance.
• Monkey SC neural responses were stronger for peri-saccadic upper visual field stimuli compared to lower visual field stimuli.

Conclusions:

• Peri-saccadic visual perception is more influenced by oculomotor spatial maps (like the SC) than by visual maps (like V1).
• This indicates that the brain's motor control system for eye movements impacts visual perception during natural behavior.
• The findings challenge traditional views of visual processing anisotropies and highlight the integration of sensory and motor systems.