title: Psychophysiological response to cognitive workload during symmetrical, asymmetrical and dual-task walking.
abstract: Walking with a lower limb prosthesis comes at a high cognitive workload for amputees, possibly affecting their mobility, safety and independency. A biocooperative prosthesis which is able to reduce the cognitive workload of walking could offer a solution. Therefore, we wanted to investigate whether different levels of cognitive workload can be assessed during symmetrical, asymmetrical and dual-task walking and to identify which parameters are the most sensitive. Twenty-four healthy subjects participated in this study. Cognitive workload was assessed through psychophysiological responses, physical and cognitive performance and subjective ratings. The results showed that breathing frequency and heart rate significantly increased, and heart rate variability significantly decreased with increasing cognitive workload during walking (p<.05). Performance measures (e.g., cadence) only changed under high cognitive workload. As a result, psychophysiological measures are the most sensitive to identify changes in cognitive workload during walking. These parameters reflect the cognitive effort necessary to maintain performance during complex walking and can easily be assessed regardless of the task. This makes them excellent candidates to feed to the control loop of a biocooperative prosthesis in order to detect the cognitive workload. This information can then be used to adapt the robotic assistance to the patient's cognitive abilities.
authors.affiliation: Department of Human Physiology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; Advanced Rehabilitation Technology and Science Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium. Electronic address: kknaepen@vub.ac.be.
authors.forename: Kristel
authors.initials: K
authors.lastname: Knaepen
authors.affiliation: Institute for Kinesiology Research, Science and Research Centre of Koper, University of Primorska, Titovtrg 4, 6000 Koper, Slovenia. Electronic address: Uros.Marusic@zrs.upr.si.
authors.forename: Uros
authors.initials: U
authors.lastname: Marusic
authors.affiliation: The BioRobotics Institute, Scuola Superiore Sant'Anna, Viale Rinaldo Piaggio 34, 56026 Pisa, Italy. Electronic address: crea.simona@gmail.com.
authors.forename: Simona
authors.initials: S
authors.lastname: Crea
authors.affiliation: Advanced Rehabilitation Technology and Science Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; Robotics and Multibody Mechanics Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium. Electronic address: carodrig@vub.ac.be.
authors.forename: Carlos D
authors.initials: CD
authors.lastname: Rodríguez Guerrero
authors.affiliation: The BioRobotics Institute, Scuola Superiore Sant'Anna, Viale Rinaldo Piaggio 34, 56026 Pisa, Italy; Don Carlo Gnocchi Foundation, Via Di Scandicci 269, 50143 Firenze, Italy. Electronic address: n.vitiello@sssup.it.
authors.forename: Nicola
authors.initials: N
authors.lastname: Vitiello
authors.affiliation: Department of Human Physiology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; Vital Signs and Performance Monitoring Research Group, Belgian Royal Military Academy, Hobbemastraat 8, 1000 Brussels, Belgium; Department of Biological Psychology, Vrije Universiteit Brussel, Brussels, Belgium. Electronic address: npattyn@vub.ac.be.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Pattyn
authors.affiliation: Vital Signs and Performance Monitoring Research Group, Belgian Royal Military Academy, Hobbemastraat 8, 1000 Brussels, Belgium; Department of Biological Psychology, Vrije Universiteit Brussel, Brussels, Belgium. Electronic address: Omairess@vub.ac.be.
authors.forename: Olivier
authors.initials: O
authors.lastname: Mairesse
authors.affiliation: Advanced Rehabilitation Technology and Science Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; Robotics and Multibody Mechanics Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium. Electronic address: dlefeber@vub.ac.be.
authors.forename: Dirk
authors.initials: D
authors.lastname: Lefeber
authors.affiliation: Department of Human Physiology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; Advanced Rehabilitation Technology and Science Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium. Electronic address: rmeeusen@vub.ac.be.
authors.forename: Romain
authors.initials: R
authors.lastname: Meeusen
mesh_terms: D000328:Adult; D000674:Amputees; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D003071:Cognition / Q000502:physiology*; D005684:Gait / Q000502:physiology; D006339:Heart Rate; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology*; D011603:Psychophysiology; D012371:Robotics; D016138:Walking / Q000502:physiology*; D055815:Young Adult
keywords: (A)symmetrical walking; Cognitive workload; Dual-task; Performance; Psychophysiological response