Abstract
Understanding when the attentional system samples from continuously changing input is important for understanding how we build an internal representation of our surroundings. Previous work looking at the latency of information extraction has found conflicting results. In paradigms where features such as color change continuously and smoothly, the color selected in response to a cue can be as long as 400 ms after the cue (Sheth, Nijhawan, & Shimojo, 2000). Conversely, when discrete stimuli such as letters are presented sequentially at the same location, researchers find selection latencies under 25 ms (Goodbourn & Holcombe, 2015). The current work proposes an “attentional drag” theory to account for this discrepancy. This theory, which has been implemented as a computational model, proposes that when attention is deployed in response to a cue, smoothly changing features temporally extend attentional engagement at that location whereas a sudden change causes rapid disengagement. The prolonged duration of attentional engagement in the smooth condition yields longer latencies in selecting feature information. In three experiments participants monitored two changing color disks (changing smoothly or pseudo-randomly). A cue (white circle) flashed around one of the disks. The disks continued to change color for another 800 ms. Participants reported the disk’s perceived color at the time of the cue using a continuous scale. Experiment 1 found that when the color changed smoothly there was a larger selection latency than when the disk’s color changed randomly (112 vs. 2 ms). Experiment 2 found this lag increased with an increase in smoothness (133 vs. 165 ms). Finally, Experiment 3 found that this later selection latency is seen when the color changes smoothly after the cue but not when the smoothness occurs only before the cue, which is consistent with our theory.