Heart-rate and blood-pressure variability during psychophysiological tasks involving speech: Influence of respiration
Changes in heart-rate and systolic arterial pressure variability (HRV and SAPV) indexes have been used in psychophysiology to assess autonomic activation, including during tasks involving speech. The current article clearly demonstrates in a sample of 25 adult subjects that the erratic and broadband respiratory patterns during such tasks violate the usual assumption that respiration is limited to the high-frequency band (0.15–0.4 Hz). For these tasks, interindividual differences and rest–task changes in HRV and SAPV in the low-frequency band (0.04–0.15 Hz) can be explained, to a large extent, by variations in the respiratory volume signal. This makes the use of HRV and SAPV as markers of autonomic function during these tasks highly questionable. Furthermore, a number of subjects with long respiratory period at rest were identified, whose presence in the sample can bias the estimation of baseline rest values.
Document Type: Research Article
Affiliations: 1: Biomedical Engineering Programme (COPPE), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil 2: MRC Epidemiological Resource Centre, Southampton General Hospital, Southampton, UK 3: Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
Publication date: 2007-09-01