Divided attention effects are larger for change detection than for simple detection

Abstract

Studies of divided visual attention have largely depended on detection and search tasks because they minimize the role of memory and decision. Recently, the change detection paradigm has been used to study divided attention and the results interpreted as due to perception. Instead, might the divided attention effects in change detection be "inflated" by memory and decision? To consider this, we compare divided attention effects for change detection and simple detection. Subjects were presented two intervals of dynamic 1/f noise patches on the left and right side of fixation and were cued beforehand to attend to either one side (selective attention) or both sides (divided attention). For the change detection task, Gabor patches were embedded in the noise on both sides, in both intervals, with a 50% chance of a 90 degree change in orientation from the first interval to the second. The probability of change was independent across sides. For the simple detection task, Gabor patches appeared in each side with 50% probability and subjects were asked to detect the presence of the patch. For the change detection task, subjects performed worse in the divided attention condition compared to the selective attention condition. However, for the simple detection task, there was almost no cost of divided attention compared to selective attention. In summary, for nearly identical stimuli, we show that the magnitude of divided attention effects depends strongly on the task. Ongoing studies examine whether these task effects depend only on perception or also on memory and/or decision. Meeting abstract presented at VSS 2017