title: Neural Correlates of Task Cost for Stance Control with an Additional Motor Task: Phase-Locked Electroencephalogram Responses.
abstract: With appropriate reallocation of central resources, the ability to maintain an erect posture is not necessarily degraded by a concurrent motor task. This study investigated the neural control of a particular postural-suprapostural procedure involving brain mechanisms to solve crosstalk between posture and motor subtasks. Participants completed a single posture task and a dual-task while concurrently conducting force-matching and maintaining a tilted stabilometer stance at a target angle. Stabilometer movements and event-related potentials (ERPs) were recorded. The added force-matching task increased the irregularity of postural response rather than the size of postural response prior to force-matching. In addition, the added force-matching task during stabilometer stance led to marked topographic ERP modulation, with greater P2 positivity in the frontal and sensorimotor-parietal areas of the N1-P2 transitional phase and in the sensorimotor-parietal area of the late P2 phase. The time-frequency distribution of the ERP primary principal component revealed that the dual-task condition manifested more pronounced delta (1-4 Hz) and beta (13-35 Hz) synchronizations but suppressed theta activity (4-8 Hz) before force-matching. The dual-task condition also manifested coherent fronto-parietal delta activity in the P2 period. In addition to a decrease in postural regularity, this study reveals spatio-temporal and temporal-spectral reorganizations of ERPs in the fronto-sensorimotor-parietal network due to the added suprapostural motor task. For a particular set of postural-suprapostural task, the behavior and neural data suggest a facilitatory role of autonomous postural response and central resource expansion with increasing interregional interactions for task-shift and planning the motor-suprapostural task.
authors.affiliation: Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan.|Institute of Allied Health Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan.
authors.forename: Ing-Shiou
authors.initials: IS
authors.lastname: Hwang
authors.affiliation: School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei 100, Taiwan.|Physical Therapy Center, National Taiwan University Hospital, Taipei 100, Taiwan.
authors.forename: Cheng-Ya
authors.initials: CY
authors.lastname: Huang
mesh_terms: D000328:Adult; D001288:Attention; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D008297:Male; D004856:Postural Balance; D011187:Posture; D011597:Psychomotor Performance; D011930:Reaction Time; D055815:Young Adult