Saadat Z, Sinaei E, Pirouzi S, Ghofrani M, Nami M. Cortical Activity During Postural Recovery in Response to Predictable and Unpredictable Perturbations in Healthy Young and Older Adults: A Quantitative EEG Assessment. BCN 2021; 12 (2) :291-300
URL:
http://bcn.iums.ac.ir/article-1-1533-en.html
1- Student Research Committee, School of Rehabilitation Sciences, Shiraz University of Medical Sciences, Shiraz, Iran.
2- Department of Neuroscience, Neuroscience Laboratory, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran.
3- Department of Physical Therapy, School of Rehabilitation Sciences, Shiraz University of Medical Sciences, Shiraz, Iran.
4- Rehabilitation Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
Abstract:
Introduction: To investigate the effects of predictable and unpredictable external perturbations on cortical activity in healthy young and older adults.
Methods: Twenty healthy older and 19 healthy young adults were exposed to predictable and unpredictable external perturbations, and their cortical activity upon postural recovery was measured using a 32-channel quantitative encephalography. The absolute spectral power and coherence z-scores of cortical waves were analyzed through a 3-way mixed ANOVA.
Results: During postural recovery from predictable perturbations, older adults exhibited higher frontoparietal beta power and higher alpha and beta coherence during the late-phase recovery than the young individuals. After unpredictable perturbations, the older group showed lower alpha power in the early phase and higher beta power in the late phase as compared to the young group. Results for the group × time and group × location interactions in the older group showed a higher alpha and beta coherence over the late phase, a higher alpha coherence in F3−P3 and F4−P4 regions, and a higher beta coherence in the F4−P4 region compared to the younger group.
Conclusion: Our results revealed that the cortical activation after external perturbations increases with aging, particularly in frontoparietal areas. A shift from automatic (subcortical level) to attentional (cortical level) processing may reflect the contribution of attentional resources for postural recovery from an external threat in older individuals.
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Highlights
● In older adults, the cortical activation, particularly in frontoparietal areas, increases after external perturbations.
● Postural recovery in response to external perturbations requires attentional resources.
● Attentional demands associated with postural recovery may increase the risk of falling among older adults.
Plain Language Summary
Cortical activity in response to external perturbations was compared between 20 healthy older adults and 19 healthy young adults using encephalographic data. The absolute power and coherence of cortical waves were analyzed after predictable and unpredictable perturbations. Our results showed higher frontoparietal beta power in both predictable and unpredictable perturbations and lower alpha power in unpredictable perturbations in older participants. This finding suggests that when the balance task becomes more difficult, the cortical activity and attentional demands increase significantly. Our findings imply greater cortical activation during postural recovery following external perturbations with increasing age. Compelling evidence on this perspective would potentially pave the way towards adopting neurorehabilitation strategies.
Type of Study:
Original |
Subject:
Clinical Neuroscience Received: 2019/06/17 | Accepted: 2020/02/16 | Published: 2021/03/1