1980 Volume 16 Issue 5 Pages 732-739
This paper deals with the information transmission characteristics by two-dimensional electrocutaneous phantom sensation. Three sets of electrodes were triangularly located on the skin just above the biceps branchii and stimuli were given to each electrode simultaneously. The effects of relative magnitudes on the mental locations of two-dimensional phantom images and their just noticeable differences were first measured. Then the channel capacity and the maximum information transmission rates were studied in this electrocutaneous communication system by phantom sensation.
The following results were obtained. (a) The mental location of the two-dimensional phantom sensation is proportional to log [E2/ (E0+E1)], in which E0, E1 and E2 are the presented energy to the electrodes, respectively. (b) The just noticeable difference of the mental location has a tendency to become larger as the location approaches to the center of the triangle formed by the electrodes. The channel capacity is estimated to be about 4[bits/symbol]from the just noticeable difference of the mental location. (c) The maximum information transmission rate is calculated to be 2.8[bits/ symbol] from the results of category discrimination tests. This value is larger than the corresponding value evaluated in other informational dimensions such as the frequency and the magnitude dimensions. Therefore this shows the fact that stimuli presented by the phantom sensation can be discriminated more easily in the absolute terms than those by other single dimensional information transmission methods. And also this is almost the same as that by vibro-tactile two-dimensional phantom sensation.
