Ambiguous distractor that disrupts the control of fixation eye movements and attentional modulation

Abstract

In this study, we conducted a numerical detection task involving the number of gaps in double rings, with dynamic random dot displays used as background motion stimuli. We controlled the intensive level of attention by regulating the contrast between the target rings and distractor rings. The task performance rates of the subjects were estimated as a relation of the percentage of coherence dots. Furthermore, we measured fixation eye movements during the tasks and analyzed the influence of subthreshold coherent motion information on involuntary eye movements such as microsaccades. Subthreshold coherent motion was found to deteriorate performance with regard to counting the gaps in the rings and the frequency of microsaccades regardless of the intensive level of attention concentration. This indicates that even if the top-down processes are sufficiently effective, bottom-up motion information can affect the control of attention and eye movements.