Generalized and lateralized effects of concurrent verbal rehearsal upon performance of sequential movements of the fingers by the left and right hands

College student subjects performed a sequential typing task requiring bilaterally synchronized movements (Experiment 1) or unilaterally synchronized movements (Experiment 2) singly, and concurrently with silent and vocal rehearsal of verbal lists varying in redundancy. Rehearsal interfered with bilaterally synchronized movements more when the right hand was leading the sequence than when the left hand led, and with movements of the right more than the left hand in unilaterally synchronized movements. Results are interpreted in terms of intrahemispheric and general capacity competition between the concurrent performances.