Vibrotactile pattern recognition on the arm and back.

A series of experiments was conducted to evaluate the effectiveness with which a tactile display mounted on either the forearm or the back can be used to communicate simple instructions and commands. In the first two sets of experiments, participants identified a vibrotactile pattern using a visual template that represented the pattern of activation. For the patterns displayed on the forearm, accuracy depended on the specific set of patterns presented and ranged from 30% to 96% correct for the individual patterns. In a second series of experiments, seven hand-and-arm signals that are used to communicate in military contexts were converted into tactile representations that were displayed on the back. These were identified accurately (98% correct) and, when only the picture of the hand signal was available, participants achieved a recognition rate of 75% correct. A further study with these seven patterns indicated that participants were still able to identify the patterns accurately (92% correct) when they were engaged in a concurrent physical or cognitive task. The results indicate the importance of evaluating tactile communication in the context of the specific patterns or messages that will be conveyed, and that with the judicious selection of tactile patterns both the arm and back provide a functional substrate for tactile communication.