title: Cardiorespiratory Information Dynamics during Mental Arithmetic and Sustained Attention.
abstract: An analysis of cardiorespiratory dynamics during mental arithmetic, which induces stress, and sustained attention was conducted using information theory. The information storage and internal information of heart rate variability (HRV) were determined respectively as the self-entropy of the tachogram, and the self-entropy of the tachogram conditioned to the knowledge of respiration. The information transfer and cross information from respiration to HRV were assessed as the transfer and cross-entropy, both measures of cardiorespiratory coupling. These information-theoretic measures identified significant nonlinearities in the cardiorespiratory time series. Additionally, it was shown that, although mental stress is related to a reduction in vagal activity, no difference in cardiorespiratory coupling was found when several mental states (rest, mental stress, sustained attention) are compared. However, the self-entropy of HRV conditioned to respiration was very informative to study the predictability of RR interval series during mental tasks, and showed higher predictability during mental arithmetic compared to sustained attention or rest.
authors.affiliation: Department of Electrical Engineering (ESAT)-STADIUS, KU Leuven, Leuven, Belgium; Medical Information Technologies Department, iMinds, Leuven, Belgium.
authors.forename: Devy
authors.initials: D
authors.lastname: Widjaja
authors.affiliation: Department of Data Analysis, Ghent University, Ghent, Belgium.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Montalto
authors.affiliation: Faculty of Psychology and Educational Sciences, Health Psychology, KU Leuven, Leuven, Belgium.
authors.forename: Elke
authors.initials: E
authors.lastname: Vlemincx
authors.affiliation: Department of Data Analysis, Ghent University, Ghent, Belgium.
authors.forename: Daniele
authors.initials: D
authors.lastname: Marinazzo
authors.affiliation: Department of Electrical Engineering (ESAT)-STADIUS, KU Leuven, Leuven, Belgium; Medical Information Technologies Department, iMinds, Leuven, Belgium.
authors.forename: Sabine
authors.initials: S
authors.lastname: Van Huffel
authors.affiliation: IRCS-FBK and BIOtech, Department of Industrial Engineering, University of Trento, Trento, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Faes
mesh_terms: D000293:Adolescent; D001288:Attention / Q000502:physiology*; D004562:Electrocardiography; D006321:Heart / Q000502:physiology*; D006801:Humans; D007257:Information Theory; D008433:Mathematics; D017711:Nonlinear Dynamics; D012119:Respiration; D012815:Signal Processing, Computer-Assisted; D013315:Stress, Psychological / Q000503:physiopathology; D055815:Young Adult