Feeling what you hear: auditory signals can modulate tactile tap perception

Abstract

We tested whether auditory sequences of beeps can modulate the tactile perception of sequences of taps (two to four taps per sequence) delivered to the index fingertip. In the first experiment, the auditory and tactile sequences were presented simultaneously. The number of beeps delivered in the auditory sequence were either the same as, less than, or more than the number of taps of the simultaneously presented tactile sequence. Though task-irrelevant (subjects were instructed to focus on the tactile stimuli), the auditory stimuli systematically modulated subjects' tactile perception; in other words subjects' responses depended significantly on the number of delivered beeps. Such modulation only occurred when the auditory and tactile stimuli were similar enough. In the second experiment, we tested whether the automatic auditory-tactile integration depends on simultaneity or whether a bias can be evoked when the auditory and tactile sequence are presented in temporal asynchrony. Audition significantly modulated tactile perception when the stimuli were presented simultaneously but this effect gradually disappeared when a temporal asynchrony was introduced between auditory and tactile stimuli. These results show that when provided with auditory and tactile sensory signals that are likely to be generated by the same stimulus, the central nervous system (CNS) tends to automatically integrate these signals.

Counting visual and tactile events: The effect of attention on multisensory integration

“…Andersen, Tiippana, and Sams (2004) extended this work by showing that the number of perceived flashes can be either increased (called fission) or decreased (called fusion) by presenting either a larger or a smaller number of irrelevant beeps in combination with the flashes. In addition to these audiovisual illusions, comparable effects have been reported for almost all other combinations of modalities (Bresciani et al, 2005;Courtney, Motes, & Hubbard, 2007;Ernst, Bresciani, Drewing, & Bülthoff, 2004;Hötting & Röder, 2004;Violentyev, Shimojo, & Shams, 2005).…”

Optimal integration of auditory and vibrotactile information for judgments of temporal order.

“…A similar phenomenon is evident in the tendencies to both perceive the rate of a rapidly fluttering bimodal rhythmic stimulus to be that of the auditory, rather than the visual, component (Recanzone, 2003;Welch, DuttonHurt & Warren, 1986) and to misperceive the number of taps to the skin in line with the number of accompanying auditory beeps (Bresciani et al, 2005).…”

Asymmetries in visuomotor recalibration of time perception: Does causal binding distort the window of integration?

“…The temporal compression observed under intentional (or causal) binding could then be explained as an instance of the more general phenomenon of multisensory integration, which involves the merging of cues from different modalities into a single percept (Ernst & Bülthoff, 2004). This occurs only within a small temporal window around simultaneity, often called the temporal window of integration (Shams et al, 2002;Bresciani et al, 2005). The 'S'-shaped compressive bias around simultaneity could well be a consequence of this window of temporal integration.…”

“…Intentional binding likely contributes to the unity assumption (Welch & Warren, 1980), which is a prerequisite for multisensory integration. Integration typically requires stimuli to occur in close temporal proximity, i.e., they should fall within a window of integration (e.g., Shams et al, 2002;Bresciani et al 2005). If intentional or causal binding only occurs for discrepancies where movement leads the temporal order, this could lead to asymmetries in processing or recalibration of visuomotor time perception, due to an asymmetrical window of integration.…”