| UAB | WORB | Rm 638 | 924 18th St South | Birmingham AL | 35294 | Lab Phone: (205) 975 3446 | |
To learn how the brain perceives visual stimuli, it is necessary to fully understand how the retina creates its neural signals from the incoming flux of light. It is known that three types of cone photoreceptors are the starting point for any signals that handle ordinary daytime vision, and each of these cone types are distinctly sensitive to either red, green, or blue light. At present, it is not completely understood how signals from these photoreceptors are combined to create percepts. Without pinning down the mechanism behind the retinal stage of visual processing, we will never know how these signals are transformed by the rest of the brain. The main impediments to solving this problem have been the inability to identify and stimulate individual cones in the intact retina. The current goal of our lab is to overcome these limitations and develop a retinal microstimulator that can visualize the cones in a living eye, identify their spectral type, and most importantly, stimulate single cones selectively and repeatably with colored light sources. Methods based on adaptive-optics technology are used to image and deliver stimuli to the cone mosaic with microscopic precision. In our experiments, we hope to reveal how cone signals are combined in the retina and the brain, thereby providing the empirical foundation necessary for future studies conducted in humans. Ultimately, the microstimulator will benefit ophthalmologists and physiologists studying normal and diseased photoreceptor function, because it allows one to probe—at a cellular level—the physiological and perceptual changes associated with cone dystrophies and colorblindness. |
Sincich Laboratory at the VSRC