Neural Activations Associated With Friction Stimulation on Touch-Screen Devices

Abstract

Tactile sensation largely influences human perception, for instance when using a mobile device or a touch screen. Active touch, which involves tactile and proprioceptive sensing under the control of movement, is the dominant tactile exploration mechanism compared to passive touch (being touched). This paper investigates the role of friction stimulation objectively and quantitatively in active touch tasks, in a real human-computer interaction on a touch-screen device. In this study, 24 participants completed an active touch task involved stroking the virtual strings of a guitar on a touch-screen device while recording the electroencephalography (EEG) signal. Statistically significant differences in beta and gamma oscillations in the middle frontal and parietal areas at the late period of the active touch task are found. Furthermore, stronger beta event-related desynchronization (ERD) and rebound in the presence of friction stimulation in the contralateral parietal area are observed. However, in the ipsilateral parietal area, there is a difference in beta oscillation only at the late period of the motor task. As for implicit emotion communication, a significant increase in emotional responses for valence, arousal, dominance, and satisfaction is observed when the friction stimulation is applied. It is argued that the friction stimulation felt by the participants' fingertip in a touch-screen device further induces cognitive processing compared to the case when no friction stimulation is applied. This study provides objective and quantitative evidence that friction stimulation is able to affect the bottom-up sensation and cognitive processing.

Keywords: EEG; active touch; haptic interfaces; neural signal processing; tactile display.

Figure 1

Block diagram of the experimental setup.

Figure 2

Schematic diagram of the experiment.

Figure 3

Topographies of beta power spectral density in the active touch task period.

Figure 4

Topographies of gamma power spectral density in the active touch task period.

Figure 5

Beta and gamma power spectral densities in the middle frontal and parietal areas and beta power spectral densities in the bilateral parietal areas (t-test, p < 0.01).

Figure 6

Participants' self reports for valence, arousal, dominance, and satisfaction (Wilcoxon signed rank test, ^**&p < 0.01; paired sample t-test, ^**p < 0.01). W indicates with friction stimulation and WO indicates without friction stimulation.