Informative Tactile Stimuli in the Perception of Direction

Three experiments evaluated the efficiency of a special tactile symbol, whose stimuli purportedly specify direction, for use in tactile diagrams for the blind. A tactile form of the conventional visual arrow symbol served as a control symbol. The directional aspects of the stimuli were easily discriminated by both blind and sighted S s. Either symbol proved effective in simple diagrams, but the special symbol was superior in more complex diagrams, suggesting an interaction effect between symbol type and diagram complexity, appearing in response latency. The special symbol was preferred by blind S s in simple and complex diagrams. Various aspects of diagram presentation also proved significant. For blind S s IQ was negatively related to response time. Sighted S s provided similar results, suggesting that effects were general. Blind S s were faster than sighted S s, tended to make more errors, and required more information about the tasks. The results were discussed considering involvement of cognitive factors and tactile sensitivity factors. General implications for symbolic displays and tactile graphics for the blind were also discussed.