Neural activity in human lateral geniculate nucleu's measured with functional MRI

Purpose. Our goal was to demonstrate that functional magnetic resonance imaging (fMRI) can measure level- of neural actîvit v in the human lateral gemiculate nuclei-4 lUIN). Method-4 Subjects viewed contrast reversing checkerboard patterns that alternated with a uniform field at 1/60 Hz. Five planes of fMRI data (echo-planar imaging. TE = 10. FA = 80, pixed size = 1.5 × 3 × 4 mm) were acquired in a nearly horizontal section that was optimized for viewing the LGN. One functional image was acquired from each plane every 2.0 seconds. Response amplitude was measure as the amplitude fo the sinusiod at the stimulus frequency (1/60) hZ) that best fil the fMRI signal at each pixel. Response phase was measure in the same planes as the functional scans. Conclusons. Functional MRI can measure contrast response functions in the human lateral geniculate nucleus. These will be important for further studies of the human LGN, and as control conditions for studies attempting to measure cortical processing.