Two distinct modes of sensory processing observed in monkey primary visual cortex (V1)
Methods The visual stimuli consisted of an array of randomly drifting Gabor patches, with a subset aligned to form a coherently drifting closed contour. This contour was designed to optimally stimulate the non-overlapping receptive fields of two or more neurons under study. Two additional salience conditions were tested by adding orientation jitter to the Gabor patches that were not stimulating the receptive fields of the recorded cells. Contours also appeared with equal probability at an alternative "control" location that was equidistant from the fixation point. The stimuli appeared 500 ms after initial fixation and the animals were free to saccade to the target as soon as they were detected. The animals received a juice reward if they performed this task correctly within 300 ms of the stimulus onset. Only correct trials were considered in this analysis. Currently, we have analyzed the responses of 110 well-isolated neurons in one animal.