User perceptions and evaluations of short vibrotactile feedback

Perceived Depth and Roughness of Virtual Buttons With Touchscreens

With the rapidly increasing penetration of touchscreens in various application sectors, more sophisticated and configurable haptic effects can be rendered on touchscreens (e.g., buttons). In this paper, we presented a design process to instantiate a wide range of vibrotactile stimuli for rendering various virtual buttons on touchscreens. We study the perceived depth and roughness of rendered virtual buttons. There are two stages: the design of the drive signals and the main study. We generated and screened drive signals to render vibrotactile stimuli for virtual buttons through varying envelope shapes, superposition methods, compound waveform composition (CWC) types, durations, and frequencies. The results show that the perceived depth of virtual buttons can be very deep, and the perceived roughness can be very rough around the resonant frequency. Perceived depth and roughness decrease when the frequency increases or decreases from the resonant frequency. A longer duration of vibrotactile stimuli and adding pulse numbers could increase the perceived depth and roughness. Perceived depth and roughness have a similar trend with varying frequencies at a fixed duration.

The Reactivation of Motion influences Size Categorization in a Visuo-Haptic Illusion

People simulate themselves moving when they view a picture, read a sentence, or simulate a situation that involves motion. The simulation of motion has often been studied in conceptual tasks such as language comprehension. However, most of these studies investigated the direct influence of motion simulation on tasks inducing motion. This article investigates whether a mo- tion induced by the reactivation of a dynamic picture can influence a task that did not require motion processing. In a first phase, a dynamic picture and a static picture were systematically presented with a vibrotactile stimulus (high or low frequency). The second phase of the experiment used a priming paradigm in which a vibrotactile stimulus was presented alone and followed by pictures of objects. Participants had to categorize objects as large or small relative to their typical size (simulated size). Results showed that when the target object was preceded by the vibrotactile stimulus previously associated with the dynamic picture, participants perceived all the objects as larger and categorized them more quickly when the objects were typically "large" and more slowly when the objects were typically "small." In light of embodied cognition theories, this bias in participants' perception is assumed to be caused by an induced forward motion. generated by the reactivated dynamic picture, which affects simulation of the size of the objects.