Conveying Looming with a Localized Tactile Cue

Abstract : Specific visual and auditory cues convey the approach of moving objects (looming). This first experiment evaluated whether tactile stimuli can convey looming. We determined whether subjects could interpret a varying vibration cue as a meaningful tacton, i.e., a simple, structured message consistent with looming. Subjects (N=35) experienced various vibration stimuli and judged (e.g., via semantic differentials) whether they could be interpreted as consistent with approaching or receding. Vibration frequency and on/off beat speed of vibration were the main stimuli studied. Results indicate that increasing the frequency of vibration over the period of stimulation was most effective in conveying a tacton consistent with looming. The best stimulus was also the one most analogous to the natural Doppler shift cue, which is used in the auditory domain for detecting looming. Beat speed has been exploited in some past tactile applications to convey closing distance, but frequency may be a more ecologically-valid cue. The general findings are consistent with past research that has implied looming as a modality-neutral response.