Cutaneous coding of optical signals: The optohapt

Means of transmuting optical signals into cutaneous patterns are sufficiently rare to warrant a fresh attempt at devising one. An instrument called the “optohapt” is described. It converts printed or typed characters into tactual signals having various spatial and temporal properties. These are impressed on nine widely scattered bodily loci. Data on discriminability of a wide range of patterns are reported, and there is proposed a promising coding system for the instrument.