Figure 4

Main effects of task on the speed and correctness of movement during rapid continuous movement. The frequency of movement in hand (a, c) and tongue (b, d) in Part 1 of Session 2 is presented in counts/s. H, independent hand task; T, independent tongue task; HT, concurrent hand- tongue task; HC, concurrent hand-cognitive task; TC, concurrent tongue-cognitive task. *, P < 0.05; **, P < 0.01.