Directing visual attention with spatially informative and spatially noninformative tactile cues.
We investigated the tactile cuing of visual spatial attention using spatially-informative (75% valid) and spatially-noninformative (25% valid) tactile cues. The participants performed a visual change detection task following the presentation of a tactile spatial cue on their back whose location corresponded to one of the four visual quadrants on a computer monitor. The participants were explicitly instructed to use the spatially-informative tactile cues but to ignore the spatially-noninformative cues. In addition to reaction time data, participants' eye-gaze was monitored as a measure of overt visual attention. The results showed that the spatially-informative tactile cues resulted in initial saccades toward the cued visual quadrants, and significantly reduced the visual change detection latencies. When spatially-noninformative tactile cues were used, the participants were largely successful at ignoring them as indicated by a saccade distribution that was independent of the quadrant that was cued, as well as the lack of a significant change in search time as compared to the baseline measure of no tactile cuing. The eye-gaze data revealed that the participants could not always completely ignore the spatially-noninformative tactile cues. Our results suggest that the tactile cuing of visual attention is natural but not automatic when the tactile cue and visual target are not collocated spatially, and that it takes effort to ignore the cues even when they are known to provide no useful information. In addition, our results confirm previous findings that spatially-informative tactile cues are especially effective at directing overt visual attention to locations that are not typically monitored visually, such as the bottom of a computer screen or the rearview mirror in an automobile.