Voluntary aspects of attentional control setting for detecting a feature-defined target

Abstract

Singleton targets that differ from distractors in a single salient attribute can be discerned regardless of the number of items in the display. Recent studies have indicated that the perception of singleton targets is facilitated by an attentional control setting. We focused on the voluntary aspect of the attentional control setting. Psychophysical and functional magnetic resonance imaging (fMRI) experiments examined the temporal characteristics of the attentional control setting by using an auditory cue. In both experiments, an auditorily cued feature-search task was used. The cue validity (valid vs. neutral) and the cue lead time (CLT) were varied. In the psychophysical experiment, we established the effect of a symbolic cue on detection of a singleton. When the CLT was short or the cue was neutral, there was no facilitation, as reflected by the slow activation of the attentional control setting. In our fMRI experiment, the brain activity indicates that this detection task activated the prefrontal cortex. These results demonstrate that the attentional control setting for facilitation of the singleton-target perception modulates activity in regions of the prefrontal cortex.