Functional near-infrared spectroscopy during optic flow with and without fixation

Area of Science:

• Neuroscience
• Vestibular System
• Visual Perception

Background:

• Visual vertigo involves dizziness and balance issues due to conflicting visual-vestibular information.
• Current treatments like optic flow exercises lack evidence-based guidelines.
• The brain's processing of optic flow stimuli remains unclear.

Purpose of the Study:

• To investigate cerebral activation during optic flow using functional near-infrared spectroscopy (fNIRS).
• To determine if visual fixation modulates brain activity during optic flow exposure.

Main Methods:

• Fifteen healthy adults experienced unidirectional optic flow in a virtual reality environment.
• Brain activity was measured using fNIRS from bilateral fronto-temporo-parietal and occipital lobes.
• Participants viewed optic flow with and without a visual fixation target.

Main Results:

• Optic flow viewing led to greater cerebral activation compared to a stationary scene.
• Enhanced activation in bilateral fronto-temporo-parietal lobes was noted when optic flow was viewed with fixation.
• fNIRS data revealed significant brain responses to visual motion stimuli.

Conclusions:

• Optic flow stimulates bilateral fronto-temporo-parietal cortical regions.
• Visual fixation during optic flow enhances activation in these key brain areas.
• Findings suggest incorporating fixation targets in habituation exercises for visual vertigo.