Integration of auditory and vibrotactile stimuli: Effects of phase and stimulus-onset asynchrony

摘要

The perceptual integration of 250 Hz, 500 ms vibrotactile and auditory tones was studied indetection experiments as a function of (1) relative phase and (2) temporal asynchrony of the tonepulses. Vibrotactile stimuli were delivered through a single-channel vibrator to the left middlefingertip and auditory stimuli were presented diotically through headphones in a background of 50dB sound pressure level broadband noise. The vibrotactile and auditory stimulus levels used eachyielded 63%-77%-correct unimodal detection performance in a 2-I, 2-AFC task. Results forcombined vibrotactile and auditory detection indicated that (1) performance improved forsynchronous presentation, (2) performance was not affected by the relative phase of the auditory andtactile sinusoidal stimuli, and (3) performance for non-overlapping stimuli improved only if thetactile stimulus preceded the auditory. The results are generally more consistent with a "PythagoreanSum" model than with either an "Algebraic Sum" or an "Optimal Single-Channel" Model ofperceptual integration. Thus, certain combinations of auditory and tactile signals result in significantintegrative effects. The lack of phase effect suggests an envelope rather than fine-structure operationfor integration. The effects of asynchronous presentation of the auditory and tactile stimuli areconsistent with time constants deduced from single-modality masking experiments.