Abstract:
Tactile apparent movement was observed under the conditions of variation in stimulus duration, frequency, and separation between two stimuli. First, optimal stimulus onset asynchrony (SOA) was determined as a function of stimulus duration using stimuli with the same frequency. Second, optimal SOA was estimated as a function of frequency, by using two stimuli with different frequencies. The optimal SOA for tactile apparent movement increased with the increases of stimulus duration. When two vibrators activate with the same frequency, the optimal SOA depends on frequency. The optimal SOA of the low-frequency stimulus (10 Hz) is longer than that of the high-frequency stimulus (250 Hz). If the first stimulus is 10 Hz and the second stimulus is 200 Hz, the optimal SOA is shorter than two stimuli with same frequency (10 Hz). The first stimulus was kept constant at 10 Hz and the second stimulus was varied in frequency. As the frequency-difference increases, the optimal SOA is decreased, but at the second stimulus of 80 Hz, the optimal SOA is similar to that of two stimuli of 200 Hz. These findings suggest that there are interactions between two channels. [Work supported by the Ministry of Education, Science and Culture, No. 62810008.]