Interaction of display mode and character size in vibrotactile letter recognition

Abstract

Research with the Tactile Vision Substitution System, a device that converts optical patterns into vibrotactile patterns for display against the back, has shown that a simple pattern, such as a letter, is more easily recognized when presented sequentially than when presented in entirety all at once. In recent work with the Optacon, another such device using the surface of the finger for display, Craig (Note 2) has found quite the opposite result over an extensive range of pattern durations. The present study shows that the superiority of sequential presentation can be obtained with the Optacon if letters considerably smaller than usual are displayed. Sequential presentation is advantageous when the pattern information essential for recognition exceeds the spatial bandwidth of the sensory surface, whether it be the finger, back, or other skin surface. In the normal usage of the Optacon, however, it appears that the spatial bandwidth of the finger suffices for the recognition of large roman letters. © 1980, The psychonomic soceity, inc.. All rights reserved.