Mapping the spatial extent of perceptive fields for flicker adaptation using retinally stabilized stimuli

Abstract

When an image is stabilized on the retina, it fades from perception due to local adaptation of neurons with receptive fields that are fixed in retinal space. We were interested in mapping the perceptive fields (PF) - the psychophysical equivalent of receptive fields - which delimit the spatial area where fading of flickered stimuli occurs. To do so, we used a tracking scanning laser ophthalmoscope to deliver stabilized stimuli to the retina. Subjects adapted to a small spot stimulus with a Gaussian intensity profile (σ = 0.56 arcminutes) that flickered at 5 Hz for 2 secs at 10 deg eccentricity. The stimulus faded after approximately 1 sec. The last onset of the stimulus was a probe flash that was spatially offset by 0–6 arcminutes in one of four cardinal directions. Subjects indicated whether the probe was visible using a 0–3 confidence rating scale. The PFs were approximately 10 arcminutes in diameter, asymmetric relative to the adapting point and vertically anisotropic. Outside of the PFs detectability increased rapidly, indicating that there are sharp borders between the PFs of stabilized flickering stimuli.

Meeting abstract presented at the 2016 OSA Fall Vision Meeting

Footnotes

 This work was supported by NIH grants R01EY023591 (A.R., A.E.B., C.M.P.) and T32EY007043 (A.E.B.), the American Optometric Foundation Ezell Fellowship (A.E.B.), and the Minnie Flaura Turner Memorial Fund for Impaired Vision Research (A.E.B.).