Speed-accuracy tradeoff during performance of a tracking task without visual feedback.

To help people with visual impairment, especially people with severely impaired vision, access graphic information on a computer screen, we have carried out fundamental research on the effect of increasing the number of detection fields. In general, application of the parallelism concept enables information to be accessed more precisely and easily when the number of sensors is high. We have developed a "Braille Box" by modifying Braille cells to form a tactile stimulator array which is compatible with the fingertip. Each pin can be controlled independently so that we can change the size and type of array in order to study the tactile perception of both simple and complex graphical forms. Our results show that by applying the parallelism concept to the detection field, people with visual impairment can increase the speed of exploration of geometric forms without decreasing the level of accuracy: thus, avoiding a speed-accuracy tradeoff. Further experiments need to be done with this Braille Box in order to improve the device and help people with visual impairment access graphic information.