Task Integration Facilitates Multitasking

Abstract

The aim of this study was to investigate multi-task integration in a continuous tracking task. We were particularly interested in how manipulating task structure in a dual-task situation affects learning of a constant segment embedded in a pursuit-tracking task. Importantly, we examined if dual-task effects could be attributed to task integration by varying the structural similarity and difficulty of the primary and secondary tasks. In Experiment 1 participants performed a pursuit tracking task while counting high-pitched tones and ignoring low-pitched tones. The tones were either presented randomly or structurally 250 ms before each tracking turn. Experiment 2 increased the motor load of the secondary tasks by asking participants to tap their feet to the tones. Experiment 3 further increased motor load of the primary task by increasing its speed and having participants tracking with their non-dominant hand. The results show that dual-task interference can be moderated by secondary task conditions that match the structure of the primary task. Therefore our results support proposals of task integration in continuous tracking paradigms. We conclude that multi-tasking is not always detrimental for motor learning but can be facilitated through task-integration.

Keywords: attention; dual-task; implicit learning; multitasking; pursuit tracking; structure.

FIGURE 1

Experiment 1: Mean RMSE over blocks, groups and segments. Error bars are standard error of the mean. The x-labels are boxed according to the days when they were completed; Blocks 1–3 were completed in day 1, blocks 4–6 were completed in day 2, and the retention and transfer blocks were completed in day 3. All blocks were performed in the group-specific conditions.

FIGURE 2

Experiment 1: Mean RMSE for all trials of block 1. Note that the Structure group starts showing smaller RMSE than the Single and Random groups after the 10th trial. Error bars are standard error of the mean.

FIGURE 3

Experiment 2: Mean RMSE over blocks, groups and segments. Error bars are standard error of the mean. The x-labels are boxed according to the days when they were completed; Blocks 1–3 were completed in day 1, blocks 4–6 were completed in day 2, and the retention and transfer blocks were completed in day 3. Single denotes a block where all groups performed only the tracking task. Note that the axes are different from those used in Figure 2.

FIGURE 4

Experiment 2: Performance measures in the secondary task. Percentage of correct responses and reaction time to the low-pitched tones and the high-pitched tones. The x-labels are boxed according to the days when they were completed. Stars indicate significant group differences.

FIGURE 5

Experiment 3: Mean RMSE over blocks, groups and segments. Error bars are standard error of the mean. The x-labels are boxed according to the days when they were completed; Blocks 1–3 were completed in day 1, blocks 4–6 were completed in day 2, and the retention and transfer blocks were completed in day 3. Single denotes a block where all groups performed only the tracking task. Catch denotes a block where all groups performed only the tracking task and all segments were pseudorandom. Note that group practice blocks 3, 4, and 6 are linked to facilitate comparison but a 10-trial catch block was completed between blocks 4 and 6. In total there were three blocks of 40 group practice trials (fewer than in the previous experiments). Note that the axes are different from those used in previous figures.

FIGURE 6

Experiment 3: Percentage of correct responses and reaction time to the low-pitched tones and the high-pitched tones in the secondary tasks. Interruptions in the line between Blocks 4 and 6 indicate that a 10-trial catch block was completed between the two blocks. The x-labels are boxed according to the days when they were completed. There were no significant group differences.