Operator orientation and compatibility in visual-motor task performance.

This experiment assessed three alternative forms of directional compatibility between control and display movement, to examine their degree of dependence on the orientation of the operator. Subjects performed a target acquisition task in each of 11 conditions which embodied the three compatibility types alone or in combination. Visual-motor (VM) compatibility was defined as display movement in a given direction in the subject's visual field produced by control movement in the same direction in the subject's 'virtual' visual field (i.e., were he or she looking at the control rather than the display). Control-display (CD) compatibility referred to congruence between control and display movements. Visual-trunk (VT) compatibility was present if a control movement was in the same direction relative to the operator's trunk as the movement of the display in the visual field. VM compatibility produced performance superior to that under CD or VT compatible conditions in all phases of the task, and was independent of the subject's physical orientation and of the target direction. Visual-motor compatibility appears to reflect a basic and general relationship between visual and motor codes in the central nervous system, and may prove a useful basis for reducing errors and enhancing performance in certain human-machine systems.