Feedback Timing upon Voluntary Heart Rate Control (II)

Abstract

The purpose of this study was to test whether it is necessary to synchronize feedback display timing with R-wave of the cardiac cycle during voluntary heart rate control. A previous study (Inamori, 1980) showed that tracking accuracy of heart rate of the R-desynchronized feedback condition was lower than that of immediate feedback condition. But it was impossible to determine whether the disturbing effect was due to R-desychronized effect or the 1/2-beat variable delay feedback effect. To investigate this problem, a 1/2-beat constant delay condition was added in this experiment. Analogue heart rate feedback of each beat and target zone were presented on a TV display. Sixteen subjects received thirty-two 100-beat trials. A11 subjects were required to put their heart rate into the target zone under four different conditions; immediate, 1/2-beat constant delay, 1/2-beat variable delay, and 1-beat delay feedback conditions. Differences between the feedback conditions were found in the tracking performance and the heart rate variabilities which were evaluated by frequency analysis of successive heart rates. The tracking accuracies were disturbed as a function of length of feedback delay, and these effects corresponded with the strength of low frequency power of heat rate variabilities. However, in both measures, the results of 1/2-beat constant delay condition were identical with those of 1/2-beat variable delay condition, suggesting that it is not necessary to, synchronize the feedback display timing with R-wave.