The effect of auditory signals on the control of the rapidity of arm movements.

An experimental study of the effect of auditory signals on the rapidity of arm movements was undertaken in 32 right-handed subjects. The task (a printed tapping test) was performed with the presence of metronome clicks intended to act as pacemakers of the subject's tapping movements. The effect of preferred hand, direction of movement (i.e. left-right and right-left) and mode of acoustic presentation (monoaural or binaural) was investigated. Results indicate that the presence of acoustic signals increases (without a concomitant decrease in accuracy) the rapidity of movements, but there is not differential increase whether the signals are delivered to the right or left ear or binaurally. Repetitive movements of the right arm are faster than those of the left; and the direction in which the movements are made influences the rapidity of performance for both arms, left-right movements being faster than those made in the right-left direction. Some theoretical intrepretations of the findings are discussed.