Faculty of Psychology, University of Iceland, Reykjavik, Iceland.
Faculty of Industrial Engineering, Mechanical Engineering and Computer Science, University of Iceland, Reykjavik, Iceland.
J Neurophysiol. 2019 Oct 1;122(4):1810-1820. doi: 10.1152/jn.00125.2019. Epub 2019 Aug 21.
Haptic illusions serve as important tools for studying neurocognitive processing of touch and can be utilized in practical contexts. We report a new spatiotemporal haptic illusion that involves mislocalization when the order of vibrotactile intensity is manipulated. We tested two types of motors mounted in a 4 × 4 array in the lower thoracic region. We created apparent movement with two successive vibrotactile stimulations of varying distance (40, 20, or 0 mm) and direction (up, down, or same) while changing the temporal order of stimulation intensity (strong-weak vs. weak-strong). Participants judged the perceived direction of movement in a 2-alternative forced-choice task. The results suggest that varying the temporal order of vibrotactile stimuli with different intensity leads to systematic localization errors: when a strong-intensity stimulus was followed by a weak-intensity stimulus, the probability that participants perceived a downward movement increased, and vice versa. The illusion is so strong that the order of the strength of stimulation determined perception even when the actual presentation movement was the opposite. We then verified this "intensity order illusion" using an open response format where observers judged the orientation of an imaginary line drawn between two sequential tactor activations. The intensity order illusion reveals a strong bias in vibrotactile perception that has strong implications for the design of haptic information systems. We report a new illusion involving mislocalization of stimulation when the order of vibrotactile intensity is manipulated. When a strong-intensity stimulus follows a weak-intensity stimulus, the probability that participants perceive an upward movement increases, and vice versa. The illusion is so strong that the order of the strength of stimulation determined perception even when the actual presentation movement was the opposite. This illusion is important for the design of vibrotactile stimulation displays.
触觉错觉是研究触觉神经认知加工的重要工具，可在实际情境中得到应用。我们报告了一种新的时空触觉错觉，当振动强度的顺序被操纵时，会出现定位错误。我们测试了两种安装在下胸区域的 4×4 阵列中的电机。我们通过连续两次以不同距离（40、20 或 0 毫米）和方向（向上、向下或相同）进行振动刺激，同时改变刺激强度的时间顺序（强-弱与弱-强）来产生明显的运动。参与者在 2 项选择强制任务中判断感知运动的方向。结果表明，改变具有不同强度的振动刺激的时间顺序会导致系统的定位错误：当强强度刺激后跟随弱强度刺激时，参与者感知向下运动的概率增加，反之亦然。错觉非常强烈，以至于刺激强度的顺序甚至决定了感知，即使实际呈现的运动是相反的。然后，我们使用开放响应格式验证了这种“强度顺序错觉”，观察者在其中判断两个连续触觉器激活之间绘制的假想线的方向。强度顺序错觉揭示了振动触觉感知中的强烈偏见，这对触觉信息系统的设计具有重要意义。我们报告了一种新的错觉，当振动强度的顺序被操纵时，会出现刺激的定位错误。当强强度刺激跟随弱强度刺激时，参与者感知向上运动的概率增加，反之亦然。错觉非常强烈，以至于即使实际呈现的运动是相反的，刺激强度的顺序也决定了感知。这种错觉对于振动触觉刺激显示器的设计很重要。
