Scene segmentation in early visual cortex during suppression of ventral stream regions

Area of Science:

• Neuroscience
• Visual Perception
• Computational Neuroscience

Background:

• Feedback modulation is crucial for early visual processing and cortical computation.
• High-level stimuli activating ventral regions typically suppress early visual cortex, often explained by predictive coding.
• Previous research linked ventral regions to object recognition and dorsal regions to spatial processing.

Purpose of the Study:

• To investigate early visual modulation during Gestalt illusion perception.
• To determine if dorsal stream mediation influences early visual cortex activity differently than ventral stream mediation.
• To examine feedback mechanisms in visual processing beyond ventral stream activation.

Main Methods:

• Utilized a bistable dynamic stimulus of moving dots creating a Gestalt illusion (moving cube) or local elements.
• Recorded differential modulations in early visual cortex (V1 and V2) during perception shifts.
• Performed correlation analyses to investigate mechanisms of foreground and background modulation.

Main Results:

• Perceptual binding into an illusory Gestalt enhanced representations of illusory lines and foreground in V1 and V2.
• Simultaneously, inducers and background elements were suppressed in early visual cortex.
• Correlation analyses indicated distinct mechanisms for foreground and background modulation.

Conclusions:

• Motion-induced Gestalt perception differentially modulates early visual cortex (V1, V2).
• These modulations occur even without activation of ventral stream object-responsive regions.
• Findings suggest feedback mechanisms in visual processing are more diverse than previously assumed, involving dorsal pathways.