Experimental test of visuomotor updating models that explain perisaccadic mislocalization

Area of Science:

• Neuroscience
• Visual Perception
• Oculomotor Control

Background:

• Perisaccadic visual mislocalization is a known phenomenon where target localization is inaccurate around the onset of eye movements (saccades).
• Existing hypotheses attribute this to factors like sluggish eye position representation, visual event filtering, or saccade-induced spatial compression.

Purpose of the Study:

• To investigate the influence of saccade amplitude and kinematics on perisaccadic mislocalization patterns.
• To differentiate between oculomotor feedback and visual perception errors as the cause of perisaccadic mislocalization.

Main Methods:

• Utilized the double-step paradigm to analyze localization errors for saccades with varying amplitudes.
• Systematically analyzed error patterns in relation to saccade properties.

Main Results:

• Perisaccadic localization errors showed minimal dependence on primary saccade amplitude across a wide range.
• A uniform shift in perceived target location, varying with amplitude only for small saccades, better explained the observed error patterns.
• The magnitude of this visual shift saturated around 10 degrees and was influenced by target duration.

Conclusions:

• The findings suggest that perisaccadic mislocalization primarily stems from errors in visual-spatial perception.
• This challenges theories relying solely on sluggish oculomotor feedback mechanisms.
• The proposed model emphasizes a perceptual shift that is largely independent of saccade amplitude for larger movements.