Motion detection is a fundamental sensory function for multiple modalities, including touch, but the mechanisms underlying tactile motion detection are not well understood. While previous findings supported the existence of high-level feature tracking, it remains unclear whether there also exist low-level motion sensing that directly detects a local spatio-temporal correlation in the skin-stimulation pattern. To elucidate this mechanism, we presented, on braille displays, tactile random-dot kinematograms, similar to those widely used in visual motion research, which enables us to independently manipulate feature trackability and various parameters of local motion. We found that a human observer is able to detect the direction of difficult-to-track tactile motions presented to the fingers and palms. In addition, the direction-discrimination performance was better when the stimuli were presented along the fingers than when presented across the fingers. These results indicate that low-level motion sensing, in addition to high-level tracking, contribute to tactile motion perception.

运动检测是包括触摸在内的多种模式的基本感觉功能，但触觉运动检测的机制尚不清楚。虽然之前的研究结果支持高级特征跟踪的存在，但目前尚不清楚是否还存在直接检测皮肤刺激模式中局部时空相关性的低级运动传感。为了阐明这一机制，我们在盲文显示器上呈现了触觉随机点运动图，类似于视觉运动研究中广泛使用的运动图，这使我们能够独立操纵特征可跟踪性和局部运动的各种参数。我们发现人类观察者能够检测手指和手掌呈现的难以追踪的触觉运动的方向。此外，当刺激沿着手指呈现时，方向辨别性能比跨手指呈现时更好。这些结果表明，除了高级跟踪之外，低级运动感知也有助于触觉运动感知。