Development of Tactile Mice for Blind Access to Computers: Importance of Stimulation Locus, Object Size, and Vibrotactile Display Resolution

Graphics are used increasingly in the interface and portrayal of information in application software used by modern computers. This approach, while of benefit to the sighted population, produces significant perceptual and usability problems for the blind. This paper presents the findings of a set of experiments that were conducted to evaluate recognition performance for unseen graphic objects when: a) vibrotactile cutaneous stimuli are directly presented to either the dominant hand tasked with maneuvering a mouse-driven screen sensor, or to the nonactive hand, b) graphical element size and geometric complexity are varied, and c) pixel-to-tactor mapping ratios are varied. Results showed that kinesthetic cues, and pixel-to-tactor resolution of the vibrotactile display were far more important in terms of recognition accuracy and response rate than the locus of cutaneous stimulation.