Saccades to partially occluded objects: Perceptual completion mediates oculomotor control.

Area of Science:

• Cognitive Neuroscience
• Visual Perception
• Oculomotor Control

Background:

• Oculomotor behavior involves directing gaze to extract information from complex scenes.
• The computation of saccades (rapid eye movements) relies on visual representations.
• Two hypotheses exist: image-based control and object-based control.

Purpose of the Study:

• To investigate the nature of visual representations guiding saccades to objects.
• To differentiate between image-based and object-based oculomotor control hypotheses.
• To determine if saccades are computed over retinal image data or 3D object representations.

Main Methods:

• Recording saccade landing positions in a naturalistic search task involving partially occluded objects.
• Designing experiments to isolate the influence of perceptual completion versus image-based cues.
• Analyzing saccade landing site biases in relation to object properties and occlusion.

Main Results:

• Saccade landing positions were biased towards the center of perceptually completed objects.
• This bias persisted even when strategically disadvantageous.
• The bias was independent of image-level differences caused by occluders.

Conclusions:

• Saccade motor programs are computed using object-level representations.
• These representations include the perceptual completion of occluded surfaces.
• Visual perception actively constructs object representations that guide oculomotor behavior.