Better than expected performance effect depends on the spatial location of visual stimulus

The process of perceptual decision-making in the real world involves aggregation of pieces of evidence into a final choice. The visual evidence is usually presented in different pieces, distributed along time and space. We wondered whether by adding variation in the location of the receiving information, subjects showed differences in how they integrated visual information. Seven participants viewed two pulses of random dots motion stimulus, separated by time gaps and in different areas of the visual field. Our findings suggest that subjects accumulate discontinuous information (over space or time), not in the same way as when they are presented continuously, at the same location or with no gaps between them. These findings indicate that the discontinuity of evidence impacts the process of evidence integration in a manner more nuanced than presumed by the theory positing the perfect integration of evidence.