Perception of sign language from an array of 27 moving spots.

Many deaf people in the USA communicate in American sign language (ASL), which has an expressive capacity equivalent to that of spoken language, although structurally independent of spoken languages. It comprises hand and arm movements often combined with particular facial gestures; together these are sufficiently precise to transmit all the complexities and innuendoes of language. Here we demonstrate that fluent ASL users can communicate easily when all they see of each other is an array of 27 light spots strategically placed on the hands and face. The results indicate the salient locations in normal sign perception, and suggest that it is feasible to transmit sign using the bandwidth of one telephone line rather than a much more expensive TV line.