Influence of motion on chromatic detection

Abstract

Intense scrutiny has been focused on whether chromatic stimuli contribute to motion perception. The present study considers a related but different question: how does motion affect chromatic detection? Detection thresholds were measured for a disk that underwent a brief (13.3 ms) chromatic change in the L/(L+M) chromatic direction. The disk's presentation sequence and speed (0-16 deg/s) were manipulated. In the coherent presentation sequence, the disk moved smoothly along a circular path centered on the fixation point. In the random presentation sequence, the disk appeared randomly at positions along the circular path. In both types of sequences, the disk underwent a brief chromatic change midway through the temporal presentation sequence. Threshold was elevated in the coherent condition compared to the random condition, and threshold decreased with an increase in speed. The threshold elevation observed in the coherent presentation sequence can be accounted for by temporal integration. The decrease in threshold with an increase in speed can be accounted for by spatial integration. The results, therefore, can be explained by spatiotemporal integration, without invoking a neural mechanism specialized for motion.

Human Visual System Integrates Color Signals along a Motion Trajectory

“…The comparison is a stimulus in which the bars are flashed simultaneously ( Figures 1C and 1D). Given that, at each retinal location, the two stimuli result in spatiotemporal patterns that are similar except for a time displacement, they should generate a similar percept if each bar flash simply remains present for a short time on the retinal coordinates [20,21] and is spatially integrated by optical mechanisms or by the standard retinotopic (spatiotemporally separable) neural color summation [10,11]. However, under certain stimulus conditions, whereas the flashed stimulus is seen as red-green stripes, the moving bars appear to have a more yellowish hue.…”

“…In comparison, the present findings reveal a more direct motion-color linkage that cannot be deduced from the previous findings. Recently, Monnier and Shevell [11] examined an effect of stimulus motion on chromaticpulse detection. Although they reported a finding that might be related to motion-based color integration (i.e., higher detection thresholds for coherent motion than for random motion), the authors only suggested an alternative interpretation in terms of motion-independent spatiotemporal integration.…”

“…Here, we report a new color illusion, motion-induced color mixing, in which moving bars, the color of each of which alternates between two colors (e.g., red and green), are perceived as the mixed color (e.g., yellow) even though the two colors are never superimposed on the retina. The magnitude of color mixture is significantly stronger than that expected from direction-insensitive spatial integration of color signals [10,11]. This illusion cannot be ascribed to optical image blurs, including those induced by chromatic aberration [12,13], or to involuntary eye movements of the observer.…”

Stream/Bounce Event Perception Reveals a Temporal Limit of Motion Correspondence Based on Surface Feature over Space and Time

“…The previous studies reported that the detection threshold for colour change (Monnier and Shevell 2004) and the response latency to colour/luminance change (Kreegipuu et al 2006) both decreased as motion speed increased. Kreegipuu et al suggested that colour change detection was promoted because a greater number of colour coding units can be activated along the motion trajectory with an increased object speed.…”

Color Signal Integration for Color Discrimination along a Long-range Apparent Motion Trajectory

“…showed observers a stimulus with horizontal apparent motion; the stimulus was composed of bar elements whose color alternated between red and green at each video frame. Color integration of a chromatic flicker on a retinal position is well known, as shown in critical flicker fusion frequency, and this integration affected chromatic detection performance for a moving target (Monnier and Shevell, 2004). In contrast, because the bar elements in Nishida et al did not overlap with one another on the retina, the color signals of the bars should not have affected each other if color integration occurred only based on the retinal coordinate.…”