Simultaneous performance on verbal, nonverbal and motor tasks by right-handed adults

A series of four dual task experiments was conducted in which different groups of right-handed Ss (N1 = 24; N2 = N3 = N4 = 18) simultaneously performed a repetitive finger tapping task in conjunction with: (a) a verbal fluency task (Experiment I); (b) listening to logical memory stories from the Weschler Memory Scale (Experiment II); (c) reading logical memory stories (Experiment III); and (d) scanning an array of faces (Experiment IV). Results indicated that all three verbal tasks produced significant asymmetrical depression in tapping performance, with the right hand being more disrupted then the left. The visuo-spatial task, however, exerted symmetrical bilateral depression of both hands. Performance on the cognitive tasks (number of words produced in the verbal fluency task; recall of stories either listened to or read, recognition of faces) was unaffected by simultaneous digital tapping.