The Effects of Spatial Attention on Temporal Integration Measured With the Ternus Display

While a large body of evidence has demonstrated the effects of attention on spatial processes, we know much less about attentional effects on the complementary temporal aspects of visual perception. To narrow this knowledge gap, we examined the effects of endogenous attention—the voluntary component of spatial attention—on temporal integration using the Ternus display. In a typical Ternus display, horizontally aligned discs shift by one position across alternating frames that are separated by a varying interframe interval. This display can induce two different motion percepts: all three discs moving together back and forth (group motion), or the two central discs seeming to remain static and the outer disk jumping across them (element motion). Several studies suggest that element motion reflects temporal integration. Thus, we used the rate of element motion percept to measure temporal integration. Attention was manipulated via the degree of certainty regarding the discs’ location (Experiment 1), or with central informative arrows (Experiment 2). The pattern of results was similar in both experiments: The participants reported perceiving element motion more often when attention was allocated in advance to the discs’ location. These results suggest that attention prolongs the period of time over which information is integrated.