Performance of a concurrent cognitive task modifies pre- and post-perturbation-evoked cortical activity

George Mochizuki; Shaun G Boe; Amanda Marlin; William E McIlroy

doi:10.1016/j.neuroscience.2017.02.014

Performance of a concurrent cognitive task modifies pre- and post-perturbation-evoked cortical activity

Neuroscience. 2017 Apr 21:348:143-152. doi: 10.1016/j.neuroscience.2017.02.014. Epub 2017 Feb 16.

Authors

George Mochizuki¹, Shaun G Boe², Amanda Marlin³, William E McIlroy⁴

Affiliations

¹ Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Physical Therapy, University of Toronto, Toronto, ON, Canada; Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada; Mobility Research Team, Toronto Rehabilitation Institute, Toronto, ON, Canada. Electronic address: george.mochizuki@sunnybrook.ca.
² Laboratory for Brain Recovery and Function, School of Physiotherapy, Dalhousie University, Halifax, NS, Canada; Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada.
³ Mobility Research Team, Toronto Rehabilitation Institute, Toronto, ON, Canada.
⁴ Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, Toronto, ON, Canada; Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada; Mobility Research Team, Toronto Rehabilitation Institute, Toronto, ON, Canada; Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada.

PMID: 28215746
DOI: 10.1016/j.neuroscience.2017.02.014

Abstract

Preparation for postural instability engages cortical resources that serve to optimize compensatory balance responses. Engagement of these cortical resources in cognitive dual-task activities may impact the ability to appropriately prepare and optimize responses to instability. The purpose of this study was to determine whether cognitive dual-task activities influenced cortical activity preceding and following postural instability. Postural instability was induced using a lean-and-release paradigm in 10 healthy participants. Perturbations were either temporally predictable (PRED) or unpredictable (UNPRED) and presented with (COG) or without a cognitive dual-task, presented in blocks of trials. The electroencephalogram was recorded from multiple frontal electrode sites. EEG data were averaged over 25-35 trials across conditions. Area under the curve of pre-perturbation cortical activity and peak latency and amplitude of post-perturbation cortical activity were quantified at the Cz site and compared across conditions. Performance of the concurrent cognitive task reduced the mean (SE) magnitude of pre-perturbation cortical activity in advance of predictable bouts of postural instability (PRED: 18.7(3.0)mVms; PRED-COG; 14.0(2.3)mVms). While the level of cognitive load influenced the amplitude of the post-perturbation N1 potential in the predictable conditions, there were no changes in N1 with a cognitive dual task during unpredictable conditions (PRED: -32.1(3.2)µV; PRED-COG: -50.8(8.4)µV; UNPRED: -65.0(12.2)µV; UNPRED-COG: -64.2(12.7)µV). Performance of the cognitive task delayed and reduced the magnitude of the initial gastrocnemius response. The findings indicate that pre- and post-perturbation cortical activity is affected by a cognitive distractor when postural instability is temporally predictable. Distraction also influences associated muscle responses.

Keywords: EEG; balance; dual-task; preparation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Attention / physiology
Cerebral Cortex / physiology*
Cognition / physiology*
Electroencephalography
Female
Humans
Male
Muscle, Skeletal / physiology
Postural Balance / physiology*
Posture / physiology*
Psychomotor Performance / physiology
Reaction Time / physiology
Young Adult