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The influence of affective state on respiratory muscle activity
Author(s) -
Westbrook Juliette,
MacBean Victoria
Publication year - 2019
Publication title -
clinical physiology and functional imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.608
H-Index - 67
eISSN - 1475-097X
pISSN - 1475-0961
DOI - 10.1111/cpf.12567
Subject(s) - medicine , respiratory system , physical medicine and rehabilitation , cardiology , physical therapy
Summary Measures of neural respiratory drive through the use of electromyography of the parasternal intercostal muscles ( EMG para) are accurate markers of respiratory load and are reflective of pulmonary function. A previous observation of a significant reduction in EMG para from a first to second measurement occasion was attributed to participants’ acclimatization to the laboratory environment and a reduction in anxiety. This study therefore aimed to investigate whether manipulation of participants’ affective state would influence EMG para and related variables. Healthy adult participants underwent measurement of EMG para and respiratory flow and volume during exposure to four conditions: no stimulus, music, and tense and calm videos. Respiratory rate ( RR ), raw neural respiratory drive index (raw NRDI , the product of EMG para in microvolts and RR ) and minute ventilation ( VE ) differed significantly across conditions: RR and VE were significantly higher in the tense condition than all other conditions (all P <0·05); raw NRDI was higher in the tense compared to the calm video condition ( P = 0·03). There was also a significant relationship between EMG para and subjective tension ratings (measured via visual analogue scale) in the tense condition (Spearman's rho = 0·508, P = 0·016), with multivariate modelling indicating significant interactions between raw NRDI and subjective ratings of both tension and calmness. This suggests that anxiety could contribute to elevated respiratory muscle activity and ventilation. Greater consideration should be given to the influence of anxiety when undertaking measurement of respiratory muscle activity to ensure data accurately represent underlying respiratory load.