Spatial stimulus–response compatibility for hand and foot controls with vertical plane visual signals

Most of the previous studies on spatial S–R compatibility have been limited to the use of hand controls with visual signals on horizontal displays. This study examined the performance of 38 right-handed and right-footed participants in a four choice spatial stimulus–response (S–R) compatibility task with the use of hand and foot controls to respond to visual signals in a vertical plane. The hand and foot dominance of participants was assessed with the Lateral Preference Inventory of Coren (1993). There was a strong spatial S–R compatibility effect in the task revealed by the significant interaction of visual signal position and response key position. The spatial compatibility effect for the above/below dimension was found to be significantly stronger than for the right/left dimension, and no prevalence of right/left over above/below spatial cue was observed in this study. In addition, S–R compatibility produced larger magnitude effect for the top signals compared with bottom ones. As expected, participants responded faster with hands than with feet, and responses from the right foot were faster than those from the left foot for the right-handed/footed participants tested here. The results of this study provide vital information for designing more effective human–machine interfaces with hand and foot controls interacting with vertical plane visual signals.

► Compatibility in both the horizontal and vertical dimensions leads to the best human performance.
► Spatial compatibility effect is greater in the above/below than right/left dimension.
► Critical response signals should be positioned at top position in a vertical display.
► Response devices for critical actions should be manipulated by the hands.