Time-frequency analysis of heart rate variability and the" short circuiting" of appraisals

Descriptors: heart rate variability, wavelet, emotionSeminal research indicated that “short circuiting” the appraisal of emotional stimuli causesreductions in autonomic arousal. The effect of these manipulations on heart rate variability(HRV), however, is unclear. In the present study, we investigated the effect of “shortcircuited” appraisals on HRV and heart period (HP) reactivity. Adult participants viewedmildly evocative films, each preceded and followed by a 20-second rest period. Prior to eachpre-film period, half of the participants received information about the content of theforthcoming film. HRV was quantified using a time-domain method (RMSSD) and atime-frequency method (continuous wavelet transform; CWT). The instantaneous power ofthe CWT between respiratory frequencies (0.15–0.40 Hz) was used as an estimate of highfrequency HRV (HF-HRV). Results indicate that providing information about emotionalstimuli affected HP, RMSSD, and HF-HRVreactivity. Participants who received informationshowed higher deltaHP relative to those who did not, and these differences were strongestduring pre-film periods. Participants who did not receive information had lower overalldeltalnRMSSD relative to those who did. These effects appear to be transient, occurring onlyin the pre-film periods of two films, and post-film period of another. Similar transient effectswere observed for deltalnHF-HRV, although there was no longer an overall group difference.These findings suggest that knowing the content of forthcoming stimuli contributes torelative increases in HRV, but this effect is stimuli specific with a rapid time-course.D.J Angus and J.A.J Heathers were both supported by Australian Postgraduate Awards.