Delayed foveal and parafoveal masks disrupt peripheral target processing

Area of Science:

• Cognitive Neuroscience
• Visual Perception
• Computational Neuroscience

Background:

• Visual perception involves feedforward and recurrent processing.
• Recurrent processing refines and stabilizes visual representations.
• Masking disrupts visual perception by interfering with processing stages.

Purpose of the Study:

• Investigate how foveal and parafoveal masks disrupt recurrent visual processing.
• Examine the temporal and spatial characteristics of visual masking.
• Understand the role of feedback in stabilizing visual representations.

Main Methods:

• Participants performed a vernier discrimination task with peripherally presented targets.
• Targets were followed by masks at various spatial locations and stimulus onset asynchronies (SOAs).
• Masks included dynamic noise or vertical lines; target and mask never overlapped retinotopically.

Main Results:

• Robust masking effects observed up to 250 ms SOAs.
• Strongest impairments occurred with parafoveal masks ~100 ms after target onset, along the fixation-target axis.
• Masking effects persisted beyond the initial feedforward sweep, even for simple tasks.

Conclusions:

• Target representations require prolonged recurrent feedback for stabilization.
• Recurrent feedback is spatially selective, extending along the fixation-target axis.
• Dynamic allocation of processing resources influences vulnerability to masking in peripheral vision.