COMBINED VISUAL DISPLAY & EYE TRACKING SYSTEM FOR HIGH FIELD FMRI STUDIES

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A significant problem in functional MRI (fMRI) studies is a satisfactory means of presenting visual stimuli within the confines of the MRI system, and presenting these stimuli stereoscopically and at high spatial resolution. A second difficulty is the need for monitoring of gaze direction in fMRI studies of the oculomotor system, in which accuracy of oculomotor responses is of great importance in interpretation of fMRI results. An additional difficulty in visual presentation is monitoring compliance with instructions as to gaze direction, which can be crucial to interpretation of fMRI results in studies of the visual system. In this project these problems are answered with the construction of a unique optical system compatible with the hardware of the UAB 4.1T MRI system. The system under construction includes a pair of high-resolution LCD screens (800x600) to be viewed by an integrated binocular optical system, which will include an adaptation of an existing computer-controlled ISCAN video-camera-based system for monitoring eye movements and gaze direction. Installation is scheduled for May 1998. Preliminary oculomotor fMRI results obtained prior to the installation of the optical system have been reported in Kidambi S et al., fMRI Detection of Frontal Eye Field Activation during Saccadic Eye Movements, Proc Intl Soc Magn Reson Med 1844, 1996.  The optical system will be invaluable in oculomotor and vision-related fMRI studies and in many fMRI studies where non-verbal responses are required. It will also allow visual studies of stereopsis and depth perception. A system with this capability will thus find broad application in fMRI studies at many institutions. Development of this system will not only significantly enhance fMRI studies at the University of Alabama at Birmingham, but will also allow investigators at other institutions to be provided with the technology to significantly enhance their fMRI studies.