Development and evaluation of vibrotactile stimuli presentation device to investigate tactile working memory

Human have five senses which are visual, auditory, smell, touch and taste. The sense of touch is occurring when the skin contact with any object and human can percept the shape, temperature, vibration of the object. As well known, the spatial density of receptors located in the human skin differed of different parts such as index finger. Therefore, the sensitivity of each finger were differed from each other. In the present study, we developed a novel automatic vibrotactile patterns delivery device that is capable of perform the tactile cognitive experiment. It can serve to determining the sensitivity of each finger that contributes to tactile spatial discrimination. The primary device consists of eight piezo-electric units, slider, hand support and a controller. The device is controlled by a computer. To evaluate the performance of the device, we conducted a basic function test. The results indicated that the device can record reliable data and control the tactile pattern position precisely. Finally, ten young subjects consented to participate in the position discrimination tasks. The subjects were asked to detect the tactile stimuli and report the location. We found that index finger has higher accuracy of vibrotactile discrimination than the other fingers. Moreover, the sensitivity of distal phalanx part is higher than middle phalanx.