A temporal window for estimating surface brightness in the Craik-O'Brien-Cornsweet effect

Area of Science:

• Visual Perception
• Neuroscience
• Computational Vision

Background:

• The Craik-O'Brien-Cornsweet effect (COCe) is a brightness illusion explained by low-level spatial filtering.
• Contextual cues, like frame elements, significantly modulate the COCe, suggesting influence from lighting priors.
• It remains unclear if contextual modulation processing is independent of the primary COCe filtering mechanism.

Purpose of the Study:

• To investigate if the processing of contextual modulation in the COCe is independent of the filtering mechanisms responsible for the main effect.
• To determine the temporal dynamics of how the visual system integrates contextual frame elements with the central edge (COC edge).

Main Methods:

• The study manipulated the temporal onset asynchrony between the COC edge and a surrounding frame element.
• Luminance contrast of the frame, durations, display conditions (interocular/binocular), and frame line types were varied.
• The magnitude of the COCe was measured under these varying conditions.

Main Results:

• A significant COCe was observed within a broad temporal window of approximately 600-800 ms (centered at 0 ms onset asynchrony).
• This temporal integration window remained consistent across variations in frame luminance contrast, element durations, display conditions, and frame line types.
• The observed temporal window for binding the COC edge and frame element (~1 s) exceeds typical visual persistence ranges.

Conclusions:

• The visual system binds the COC edge and frame element over an extended temporal window (~1 s) for surface brightness estimation.
• Information from the basic spatial filtering mechanism and contextual cue processing are handled separately and integrated later.
• This suggests a multi-stage processing architecture for visual illusions influenced by context.