A binocular rivalry study of motion perception in the human brain

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Visual Perception

Background:

• Understanding the neural basis of conscious perception is a key challenge in neuroscience.
• Binocular rivalry is a paradigm used to separate constant visual stimuli from changing conscious experience.
• Previous studies have identified visual areas involved in motion processing, but their role in conscious perception remains debated.

Purpose of the Study:

• To investigate how brain activity in visual areas changes with conscious perception of motion during binocular rivalry.
• To determine if areas primarily involved in motion processing also contribute to the conscious experience of motion.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activity in human participants.
• A dichoptic stimulation paradigm presented competing random dot patterns with different motion coherence and colors.
• Participants reported their conscious perception, which alternated between coherent motion and motion noise.

Main Results:

• Activity in visual areas, notably V5, V3A, and LOC, modulated with the participants' conscious perception of motion.
• Higher brain activity was observed during the perception of coherent motion compared to motion noise.
• These areas, previously implicated in motion processing, were shown to be involved in conscious motion perception.

Conclusions:

• The findings suggest that brain areas involved in processing visual attributes are also integral to the conscious perception of those attributes.
• There is a lack of a clear distinction between 'processing' and 'perceptual' areas in the visual system.
• Conscious visual experience arises from the integrated activity of networks involved in both sensory processing and perception.