Selective and Divided Attention for Vibrotactile Stimuli on Both Arms

The present study investigates how reliably one can selectively attend to vibrotactile stimuli, as well as what characteristics of the attended and unattended stimuli affect attention. Participants wore one tactile display on the forearm and another on the opposite upper arm. They were trained to identify nine stimuli varying in location and frequency and tested on stimulus identification under various conditions: attending to one arm when only one arm was stimulated, selectively attending to one arm when both were stimulated, or attending to both arms when both were stimulated. The results demonstrate 92% accuracy for the single-arm stimulated conditions, 82% accuracy for the selective attention conditions, and a significantly lower accuracy of 50% when attending to both arms. Accuracy was higher for the slightly delayed stimulus when selectively attending. Estimates of information transfer indicate that participants can selectively attend to three locations and two frequencies with high accuracy when attending to a single arm. About 24 combinations of stimulus alternatives on the left and right arms could be reliably identified when attending to both arms.