Estimating receptive field profiles of specific visual fields

Abstract

The population receptive field (pRF) model allows researchers to estimate eccentricity, polarity, and size parameters in the visual cortex. Canonically, the visual stimulation area for pRF experiments is kept at maximum to map the whole human visual cortex. In this study, we tried to map a specific location of the visual field. We performed pRF experiments with stimulus at maximum size, and at a specific location on the stimulation screen. In our local pRF experiments, the area of stimulation was limited to 150 arcminutes, located at 240 degrees polar angle (7 o'clock) and 4 degrees of eccentricity from the fixation point. A bar-shaped stimulus, texture-mapped with a dynamic flickering checkerboard pattern, systematically traversed this area. The resulting regular (i.e. maximum field) and local pRF maps were located around dorsal V1 and V2 regions. Moreover, the local pRF maps were congruent to the globally estimated location. Our results demonstrate that stimulating a specific visual field may be utilized with fewer measurements in estimating the profile of a given visual field. In future, we aim to integrate this method to detect learning-induced changes in regions of the visual cortex encoding the retinotopic location of task-relevant stimuli.