Exploring Binocular Visual Attention by Presenting Rapid Dichoptic and Dioptic Series

Area of Science:

• Cognitive Neuroscience
• Visual Perception
• Psychology

Background:

• The Attentional Blink (AB) is a phenomenon where attention is impaired for a second target if it appears soon after a first target.
• Understanding attentional distribution in binocular vision is crucial for explaining visual processing limitations.

Purpose of the Study:

• To investigate attentional distribution in a binocular visual system using Rapid Serial Visual Presentation (RSVP) tasks under Attentional Blink (AB) protocols.
• To determine if attention is captured by a monocular channel under interocular competition during dichoptic RSVP.
• To differentiate the effects of interocular competition versus visual contrast reduction on AB performance.

Main Methods:

• Experiment 1: Dichoptic RSVP to assess attentional capture by monocular channels under interocular competition.
• Experiment 2: Monoptic RSVP (with both or one eye) to control for attentional allocation to a single eye.
• Experiment 3: Control experiment to isolate effects of interocular competition from diminished visual contrast.

Main Results:

• Dichoptic presentations delayed the 'type' stage of the Wyble's eSTST model, postponing tokenization.
• Monocular conditions showed visual attenuation due to target-frame fusion.
• Eye occlusion in Experiment 2 confirmed attentional allocation to monocular channels.
• Experiment 3 showed monocular performance differed from interocular competition, with rivalry conditions having lower detection rates.

Conclusions:

• The AB effect is attenuated or absent in dichoptic settings, highlighting differences between dichoptic and monoptic stimulus presentation.
• Monoptic presentation and binocular fusion stages appear necessary for attentional allocation and the manifestation of the AB effect.
• Findings suggest that interocular competition itself does not solely account for the observed results in dichoptic settings.