Physiological changes in response to apnea impact the timing of motor representations: a preliminary study

Abstract

Background: Reduced physiological arousal in response to breath-holding affects internal clock processes, leading swimmers to underestimate the time spent under apnea. We investigated whether reduced physiological arousal during static apnea was likely to affect the temporal organization of motor imagery (MI).

Methods: Fourteen inter-regional to national breath-holding athletes mentally and physically performed two 15 m swimming tasks of identical durations. They performed the two sequences in a counterbalanced order, the first while breathing normally using a scuba, the second under apnea. We assessed MI duration immediately after completion of the corresponding task. Athletes performed MI with and without holding breath.

Results: MI durations (26.1 s ± 8.22) were significantly shorter than actual durations (29.7 s ± 7.6) without holding breath. Apnea increased MI durations by 10% (± 5%). Heart rate decrease in response to breath-holding correlated with MI durations increase (p < .01). Under apnea, participants achieved temporal congruence between MI and PP only when performing MI of the apnea swimming task. Self-report data indicated greater ease when MI was performed in a physiological arousal state congruent with that of the corresponding motor task.

Conclusions: Physiological arousal affected the durations of MI through its effects on internal clock processes and by impacting the congruency in physiological body states between overt and covert motor performance. Present findings have potential implications with regards to the possibility of preventing underestimation of durations spent under a state of reduced physiological arousal.

Figure 1

Overhead view of experimental settings for the two sequential swimming tasks. MI: Motor Imagery.

Figure 2

Physical practice and motor imagery durations during breathing and apnea swimming tasks. Error bars represent mean standard error. Only significant differences were graphically represented. PP: Physical Practice. Ɨ: p < .10, *: p < .05, **: p < .01, ***: p < .001.

Figure 3

Correlations between variations in heart rate (percentage from basal values) and motor imagery duration changes between normal breathing and apnea conditions, for the apnea (left panel) and breathing (right panel) swimming tasks. MI: Motor imagery, HR: Heart rate.