Behavioral data and neural correlates for postural prioritization and flexible resource allocation in concurrent postural and motor tasks

Abstract

This study was undertaken to investigate the reciprocity effect between postural and suprapostural performances and its underlying neural mechanisms wherein subjects executed a perceptual-motor suprapostural task and maintained steady upright postures. Fourteen healthy individuals conducted force-matching maneuvers (static vs. dynamic) under two stance conditions (bipedal stance vs. unipedal stance); meanwhile, force-matching error, center of pressure dynamics, event-related potentials (ERPs), and the movement-related potential (MRP) were monitored. The behavioral results showed that force-matching error and postural sway were differently modulated by variations in stance pattern and force-matching version. Increase in postural challenge undermined the precision of static force-matching but facilitated a dynamic force-matching task. Both static and dynamic force-matching tasks improved postural control of unipedal stance but not of bipedal stance, in reference to the control conditions. ERP results revealed a stance-dependent N1 response, which was greater around the parietal cortex in the unipedal stance conditions. Instead, P2 was modulated by the effect of the suprapostural motor task, with a smaller P2 in the right parietal cortex for dynamic force-matching. Spatiotemporal evolution of the MRP commenced at the left frontal-central area and spread bilaterally over the frontal-central and parietal cortex. MRP onset was subject to an analogous interaction effect on force-matching performance. Our findings suggest postural prioritization and a structural alternation effect of stance pattern on postural performance, relevant to implicit expansion and selective allocation of central resources for relative task-loads of a postural-suprapostural task.

Visuospatial Tasks Affect Locomotor Control More than Nonspatial Tasks in Older People

“…Previous dual task balance studies [43] – [45] have found older adults tend to prioritize the motor tasks (i.e. postural control, and balance recovery on a moving platform) and perform significantly worse in cognitive tasks in dual task conditions.…”

The role of prefrontal cortex during postural control in Parkinsonian syndromes a functional near-infrared spectroscopy study

“…Postural control mechanisms depend on sensory information received from the visual, proprioceptive, and vestibular systems as well as appropriate motor outputs. As postural conditions become more challenging (e.g., standing on a narrow support, unipedal stance, or even dual-tasking), regions including the prefrontal cortex (PFC; Mihara et al, 2008) and parietal lobes (Mihara et al, 2008; Huang and Hwang, 2013) become progressively more involved in its monitoring. An increase in cortical involvement has been demonstrated in normal aging (Zwergal et al, 2012; Sullivan et al, 2009), especially during challenging conditions (Goble et al, 2011).…”

Neural Correlates of Task Cost for Stance Control with an Additional Motor Task: Phase-Locked Electroencephalogram Responses

“…In the concurrent execution of unrelated visual perception and working memory tasks, beta oscillation (18–24 Hz) was enhanced over that in the single-task condition, functionally serving to interface frontal-executive and occipitoparietal-perceptual processes [ 19 ]. Our previous work on a posture-motor task also revealed that ERPs in the fronto-parietal networks are important in monitoring of the attentional states in a postural-suprapostural task [ 20 , 21 ]. While maintaining upright stance and performing a force-matching task (a motor-suprapostural task), N1 negativity varied positively with the level of postural instability [ 20 , 21 ].…”

“…Our previous work on a posture-motor task also revealed that ERPs in the fronto-parietal networks are important in monitoring of the attentional states in a postural-suprapostural task [ 20 , 21 ]. While maintaining upright stance and performing a force-matching task (a motor-suprapostural task), N1 negativity varied positively with the level of postural instability [ 20 , 21 ]. This N1 negativity of posture-related ERP is thought to originate in the fronto-central regions [ 22 ], and to be relayed to anticipatory arousal [ 23 ] and sensory processing of postural perturbation [ 24 , 25 ].…”

“…This N1 negativity of posture-related ERP is thought to originate in the fronto-central regions [ 22 ], and to be relayed to anticipatory arousal [ 23 ] and sensory processing of postural perturbation [ 24 , 25 ]. On the other hand, P2 positivity was related inversely to the task-load of the secondary force-matching task [ 20 ].…”