Many electronic devices that we use in our daily lives provide inputs that
need to be processed and integrated by our senses. For instance, ringing,
vibrating, and flashing indicate incoming calls and messages in smartphones.
Whether the presentation of multiple smartphone stimuli simultaneously
provides an advantage over the processing of the same stimuli presented in
isolation has not yet been investigated. In this behavioral study we examined
multisensory processing between visual (V), tactile (T), and auditory (A)
stimuli produced by a smartphone. Unisensory V, T, and A stimuli as well as
VA, AT, VT, and trisensory VAT stimuli were presented in random order.
Participants responded to any stimulus appearance by touching the smartphone
screen using the stimulated hand (Experiment 1), or the non-stimulated hand
(Experiment 2). We examined violations of the race model to test whether
shorter response times to multisensory stimuli exceed probability summations
of unisensory stimuli. Significant violations of the race model, indicative of
multisensory processing, were found for VA stimuli in both experiments and for
VT stimuli in Experiment 1. Across participants, the strength of this effect
was not associated with prior learning experience and daily use of
smartphones. This indicates that this integration effect, similar to what has
been previously reported for the integration of semantically meaningless
stimuli, could involve bottom-up driven multisensory processes. Our study
demonstrates for the first time that multisensory processing of smartphone
stimuli facilitates taking a call. Thus, research on multisensory integration
should be taken into consideration when designing electronic devices such as
smartphones