Validity of haptic cues and its effect on priming visual spatial attention

This study investigated cross-modal links in attention between haptics and vision. A visual change-detection task was used as a measure of visual attention. Haptic taps on the back was used to prompt the user the visual quadrant within which changes occurred. The location of the haptic cues was consistent with the quadrant of the visual changes on either 80% or 20% of the trials. Ten subjects were randomly assigned to the two test conditions. The subjects were informed of the validity of the haptic cues before the experiments. We measured the effectiveness of haptic cues in terms of the changes in detection times in the visual task. Our results indicated that for the subjects in the 80% validity group, detection times decreased significantly with valid haptic cues, and increased significantly with invalid haptic cues. For the subjects in the 20% validity group, however, the results were less consistent. Some of the subjects benefited from haptic cues, while others managed to ignore the (mostly invalid) haptic cues. These results are interpreted as evidence that the use of haptic cues to reorient a person's visual spatial attention is natural and intuitive when the validity of the haptic cues is high. It is also concluded that the observed cross-modal attentional links between haptics and vision may involve a voluntary shift in attention as supposed to a purely involuntary mechanism.