The differential effect of vibrotactile and auditory cues on visual spatial attention

Previous research has shown that the presentation of spatially predictive auditory and vibrotactile warning signals can facilitate driver responses to driving events seen through the windscreen or rearview mirror. The present study investigated whether this facilitation reflects the priming of the appropriate response (i.e. braking vs. accelerating) or an attentional cuing effect (i.e. a perceptual benefit that facilitates subsequent behavioural responding). In the experiments reported here, participants had to discriminate the colour of a number plate (red vs. blue) following the presentation of either spatially predictive vibrotactile (experiment 1) or auditory (experiment 2) warning signals that indicated the likely location (front or back) of the visual target, while simultaneously performing a highly attention-demanding rapid serial visual presentation task. Numberplate discrimination performance was facilitated following the presentation of valid auditory cues, but not following the presentation of equally informative vibrotactile cues. The use of an orthogonal spatial cuing design enabled with us to rule out of a potential response priming account of these data. The results suggest that whilst directional congruency between a warning signal and a target event may be sufficient to facilitate performance due to the priming of the appropriate response, attentional facilitation effects may also require the co-location of the cue and target within the same functional region of space.