Investigating Changes in Real-time Conscious Postural Processing by Older Adults during Different Stance Positions Using Electroencephalography Coherence

ABSTRACT

Background/Study Context: Adjustments of posture in response to balance challenges may lead to subsequent increases in conscious posture processing. If cognitive resources are stretched by conscious processing of postural responses fewer resources will be available to attend to environmental trip or fall hazards. The objective of the study was to explore brain activity related to conscious processing of posture as a function of movement specific reinvestment and fear of falling.

Method: Forty-three older adults (M = 71.4, SD = 4.1) stood with a wide or narrow stance on a force-plate while neural coherence between verbal-analytical (T3) and motor planning (Fz) regions of the brain was assessed using electroencephalography. The propensity for movement specific reinvestment was assessed using the Chinese version Movement Specific Reinvestment Scale (MSRS-C) and fear of falling was assessed using the Chinese version Fall Efficacy Scale International (FES-I[CH]).

Results: Scores from the MSRS-C were negatively correlated with changes in T3-Fz coherence that occurred when participants shifted from wide to narrow stance. Together, MSRS-C and FES-I(CH) uniquely predicted the percentage change in T3-Fz coherence between the two stance conditions.

Conclusion: Presented with two postural tasks of different complexities, participants with a lower propensity for conscious control of their movements (movement specific reinvestment) exhibited larger changes in real-time brain activity (neural coherence) associated with conscious postural processing.

Acknowledgments

The authors are grateful to Dr. Liis Uiga for her insights, the staff at Chung Hok Social Center for the Elderly for their assistance in participant recruitment, and the participants who took part in the study.

Notes

1. Papers by Bellomo et al. (2018) Gallicchio et al. (2016), and van Dujin et al. (2017) used the term T7 and T8 from the newer EEG recording systems to denote the same electrode position as T3 and T4 (respectively) from the older EEG recording systems.

2. Thirty-three participants also completed a 20-s tandem stance task (with and without holding a tray of water, randomized order). However, some participants placed one foot diagonally ahead of the other and did not perform a true tandem stance (placing one foot directly in front of the other, heel-to-toe), even though they were able to do so for 30 s during the Berg Balance Scale assessment. This may have confounded the sway and T3-Fz coherence measures, so the data were excluded from the analysis.

Additional information

Funding

The work described in this article was supported by a grant (Early Career Scheme) from the Research Grants Council, University Grants Committee of the Hong Kong Special Administrative Region, China [Grant number 27608815]. The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.