Dual-task motor performance with a tongue-operated assistive technology compared with hand operations

Thirteen young able-bodied adults performed rapid and slow goal-directed movements of hand and tongue (with TDS) with and without a concurrent motor (hand or tongue) or cognitive (arithmetic and memory) task. Changes in reaction time, completion time, speed, correctness, accuracy, variability of displacement, and variability of time due to the addition of a concurrent task were compared between hand and tongue.The influence of an additional concurrent task on motor performance was similar between the hand and tongue for slow movement in controlling their displacement. In rapid movement with a concurrent motor task, most aspects of motor performance were degraded in hand, while tongue speed during rapid continuous task was maintained. With a concurrent cognitive task, most aspects of motor performance were degraded in tongue, while hand accuracy during the rapid discrete task and hand speed during the rapid continuous task were maintained.Rapid goal-directed hand and tongue movements were more consistently susceptible to interference from concurrent motor and cognitive tasks, respectively, compared with the other movement.Hand motor functions are essential in daily life, including occupational tasks, because the use of the hands plays critical roles in control, navigation, and communication. In individuals who have impaired or disabled motor functions in one of the hands (e.g., unilateral amputation, hemiplegia, and incomplete spinal cord injury), an alternative to the hand is required for performing concurrent motor tasks that are usually accomplished with two hands in able-bodied individuals. For example, they would need a functional actuator that can issue a series of commands (e.g. pressing a series of keys, drawing a line) while the able hand is manipulating an object. The speed, accuracy, and variability of performance in the actuator influence the accomplishment of the task. An able foot may be an option for such an alternative, but it is not readily available