The effect of motor-respiratory coordination on the precision of tracking movements: influence of attention, task complexity and training.

Purpose: We investigated motor-respiratory coordination (MRC) in visually guided forearm tracking movements focusing on two main questions: (1) Does attentional demand, training or complexity of the tracking task have an effect on the degree of MRC? (2) Does MRC impair the precision of those movements? We hypothesized that (1) enhanced attention to the tracking task and training increase the degree of MRC while higher task complexity would reduce it, and (2) MRC impairs tracking precision.

Methods: Thirty-five volunteers performed eight tracking trials with several conditions: positive (direct) signal-response relation (SRR), negative (inverse) SRR to increase task complexity, specific instruction for enhanced attention to maximize tracking precision ("strict" instruction), and specific instruction that tracking precision would not be evaluated ("relaxed" instruction). The trials with positive and negative SRR were performed three times each to study training effects.

Phase-dependence of breathing and finger tracking movements during normocapnia and hypercapnia.

The coordination between breathing and other motor activities usually implies that the respiratory rhythm has become entrained by the rhythm of the simultaneous movement. Our hypothesis was that by increasing the respiratory drive, e.g.