PMC4000669_01
PMC4000669_02
Patterns of cognitive-motor interference. Positive values for dual-task effects (DTE) indicate that performance improved in dual-task condition relative to single-task performance; negative values for DTE indicate that performance deteriorated in dual-task condition relative to single-task performance. Figure adapted from conceptual framework of Plummer et al..
SRT2014-538602.001.jpg
PMC4000669_02_SRT2014-538602.001.jpg
fig1
Plots showing patterns of cognitive-motor interference for each participant for each cognitive-motor dual-task combination before and after the intervention. Dual-task effects (DTE) represent percent change relative to single-task performance and are calculated by dividing the difference between single-task and dual-task values by the single-task value, expressed as a percentage. Positive values for DTE indicate that performance improved in the dual-task condition relative to single-task performance; negative values for DTE indicate that performance deteriorated in dual-task condition relative to single-task performance. DTEg is DTE on gait speed; DTEc is composite DTE for the three cognitive tasks (reaction time and accuracy for Stroop and clock tasks, clauses per utterance and pauses per utterance for spontaneous speech task).
SRT2014-538602.002.jpg
PMC4000669_02_SRT2014-538602.002.jpg
fig2
The data in Figure 2 indicate clearly the consistent negative DTE on gait speed (i.e., DTEg values consistently below the horizontal dotted line) and a range of positive and negative DTE in the cognitive task (i.e., DTEc values left and right of the vertical dotted line). Another noteworthy observation of the data in Figure 2 is the variability in dual-task interference across tasks and between participants. Stroop and clock dual-tasks at baseline, but mutual interference after intervention in both the Stroop and clock dual-tasks (Figure 2). Specifically, after the intervention, there were smaller dual-task costs on gait speed in both tasks, but this came at a cost to cognitive-task performance. His cognitive-motor interference pattern was different for the speech dual-task; he had mutual interference at baseline (with greater dual-task costs on speech than gait), but demonstrated cognitive-priority trade-off after the intervention (Figure 2). Summarizing the data illustrated in Figure 2, Participants 2, 4, 5, and 7 demonstrated improved dual-task capacity in the Stroop dual-task after intervention; their dual-task interference "point" for the Stroop dual-task was closer to the no interference region after intervention. However, the pattern change was not consistent (see Figure 2).