Abstract
The experience of touch is often accompanied by visual confirmation. A light tap on the arm, for instance, might come with the sight of a friend's hand, a landing bug, or an experimenter's probe. We explored this link between vision and touch by investigating how a visual stimulus can modulate the perception of illusory touch. The cutaneous rabbit illusion is a robust tactile illusion that results from two discrete sets of taps delivered at separate locations on the body—traditionally, two points on the forearm. Rather than feeling taps at the two veridical locations, subjects experience a series of taps “hopping” along the skin's surface between the two points. Using light emitting diodes (LEDs) at the true and illusory sites of tactile sensation, we tested whether visual stimuli can enhance or attenuate perception of the cutaneous rabbit illusion. The results from an initial experiment suggest that LED activation mimicking the “hopping” percept strengthens the illusion, whereas flashing lights at the discrete tactile stimulation sites weakens it. Further experiments aim to verify that these reports reflect subjects' actual experience and not a response bias.