RT Journal Article A1 Itzhaki, D. A1 Nelson, D. R. A1 Grinvald, A. T1 Direct Observation of Multiple Functional Intrinsic Signals Induced by Patterned Visible Light Stimuli JF Investigative Ophthalmology & Visual Science JO Invest. Ophthalmol. Vis. Sci. YR 2007 VO 48 IS 13 SP 1952 OP 1952 SN 1552-5783 AB Retinal reflectance changes in response to stimulation carry information about metabolic processes underlying light responses in the retina. The Retinal Function Imager (RFI, Optical Imaging, Ltd.) was used to non-invasively image induced reflectance changes in monkey and human retina. The RFI measures functional signals in retinal image series recorded at chosen wavelengths. We measured changes in retinal reflectance during 12-second trials with two visual stimulus test patterns and blank as a control. A patterned stimulus flashed once or at 4-30Hz during recording in infrared from eyes of anesthetized monkeys or awake human. Multiple intrinsic functional signals were clearly resolved, varying in amplitude and duration and yielding a change of up to 0.5% in retinal reflectance. The extent of the spatially specific response matched the stimulus patterns. Stimulus wavelength, frequency, duration and intensity all strongly affected the signal. The measured optical signals provide information about activity-dependent metabolic processes in the retina. The localized signals also provide an objective indicator of retinal function, suggesting clinical applications. RD 3/2/2021