Effect of Remote Masking on Detection of Electrovibration

Abstract

Masking has been used to study human perception of tactile stimuli, including those created on haptic touch screens. Earlier studies have investigated the effect of in-site masking on tactile perception of electrovibration. In this study, we investigated whether it is possible to change the detection threshold of electrovibration at fingertip of index finger via remote masking, i.e. by applying a (mechanical) vibrotactile stimulus on the proximal phalanx of the same finger. The masking stimuli were generated by a voice coil (Haptuator). For eight participants, we first measured the detection thresholds for electrovibration at the fingertip and for vibrotactile stimuli at the proximal phalanx. Then, the vibrations on the skin were measured at four different locations on the index finger of subjects to investigate how the mechanical masking stimulus propagated as the masking level was varied. Finally, electrovibration thresholds were measured in the presence of vibrotactile masking stimuli. Our results show that vibrotactile masking stimuli generated sub-threshold vibrations around fingertip and, hence, probably did not mechanically interfere with the electrovibration stimulus. However, there was a clear psychophysical masking effect due to central neural processes. Electrovibration absolute threshold increased approximately 0.19 dB for each dB increase in the masking level.

Effect of Remote Masking on Tactile Perception of Electrovibration

“…This behaviour is similar to the masking results reported in vibrotactile literature, which suggests a similar neural mechanism in detection and masking of electrovibration and vibrotactile stimuli. We refer readers to our earlier publication [25] for detailed comparison of our results with earlier studies and the possible reasons for the differences between the results.…”

“…In this study, we build up on our earlier work [25] where the effect of directly applied mechanical vibrations on electrovibration absolute detection threshold was studied. We extended our research through studying the effect of similar mechanical vibration on electrovibration intensity difference threshold and explained the outcomes of experimental results using a model based on signal energies of hypothetical neural activations.…”

On the perceived realism of virtual textures rendered by a vibrotactile wearable ring display

“…This result is unexpected because when humans interact with surfaces with their fingertips, they do not feel only contact vibrations but also other properties, such as friction, thermal conductance, and stiffness, which the participants were deprived of in contactless conditions. Moreover, there is evidence in the literature [29], [30] that remote vibrotactile stimulus can alter the perception of another at the fingertip. However, we did not observe those in our experiments.…”

On the perceived realism of virtual textures rendered by a vibrotactile wearable ring display

“…This result is unexpected because when humans interact with surfaces with their fingertips, they do not feel only contact vibrations but also other properties, such as friction, thermal conductance, and stiffness, which the participants were deprived of in contactless conditions. Moreover, there is evidence in the literature [29], [30] that remote vibrotactile stimulus can alter the perception of another at the fingertip. However, we did not observe those in our experiments.…”