MRI Stereoscope: A Miniature Stereoscope for Human Neuroimaging

Area of Science:

• Neuroscience
• Visual Perception
• Medical Imaging

Background:

• Stereoscopic vision, the perception of depth, relies on processing independent visual input from each eye.
• Studying brain mechanisms of stereoscopic vision noninvasively requires presenting distinct images to each eye (dichoptic displays) within magnetic resonance imaging (MRI) scanners.
• Existing dichoptic display solutions for MRI are often technically complex and expensive.

Purpose of the Study:

• To introduce and validate a novel, affordable, and open-source miniature stereoscope system for use inside MRI scanners.
• To demonstrate the system's capability in delivering high-quality dichoptic images for neuroscience research.
• To investigate neural activation patterns associated with stereoscopic depth perception during MRI acquisition.

Main Methods:

• Development of an 'MRI stereoscope' utilizing standard MRI equipment (head coil, display screen) and common display technology.
• Presentation of binocular disparity stimuli to six human participants within a 3T MRI scanner.
• Recording of neural activation using functional MRI (fMRI) to assess responses to visual stimuli.

Main Results:

• The MRI stereoscope successfully delivered dichoptic images, eliciting the perception of stereoscopic depth.
• Significant neural activation was observed in the dorsal and ventral extra-striate visual cortex when processing large binocular disparities.
• Binocularly anti-correlated stimuli, which do not create a sense of depth, did not evoke comparable neural responses.

Conclusions:

• The developed MRI stereoscope serves as a proof-of-concept for delivering effective dichoptic stimuli during MRI scans.
• This affordable and accessible tool can facilitate the study of brain mechanisms underlying stereoscopic vision and depth perception.
• The MRI stereoscope has potential applications in addressing fundamental questions in perception and consciousness research.