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Sensory manipulation results in increased dorsolateral prefrontal cortex activation during static postural balance in sedentary older adults: an fNIRS study

journal contribution
posted on 2018-10-01, 00:00 authored by Wei-Peng TeoWei-Peng Teo, Alicia M Goodwill, Ashlee HendyAshlee Hendy, Makii Muthalib, Helen MacphersonHelen Macpherson
BACKGROUND: The dorsolateral prefrontal cortex (DLPFC) is involved with allocating attentional resources to maintain postural control. However, it is unknown whether age-related structural and functional declines of the DLPFC may impair postural control during sensory manipulation. In this study, we aim to understand the effects of aging on the DLPFC when sensory cues were removed or presented inaccurately (i.e., increased sensory complexity) during the sensory orientation test (SOT). METHODS: Twenty young (18-25 years) and 18 older (66-73 years) healthy adults were recruited to undertake the SOT, which consisted of six conditions aimed at removing or disrupting the visual, vestibular, and proprioceptive senses. During these six SOT conditions, functional near-infrared spectroscopy (fNIRS), consisting of eight transmitter-receiver optode pairs (four channels over the left and right DLPFC), was used to measure hemodynamic responses (i.e., changes in oxy- [O2 Hb] and deoxyhemoglobin [HHb]) from the bilateral DLPFC. RESULTS: Our results show an increase in bilateral DLPFC activation (i.e., increase in O2 Hb and concomitant smaller decrease in HHb) with increasing sensory complexity in both young and older adults. The increase in left and right DLPFC activation during more complex sensory conditions was greater, which was concomitant with reduced balance performance in older adults compared to younger adults. Furthermore, we observed a right lateralized DLPFC activation in younger adults. Finally, a significant positive association was observed between balance performance and increased bilateral DLPFC activation particularly for SOT conditions with greater sensory disruptions. CONCLUSION: Our findings highlight the involvement of the DLPFC in maintaining postural control, particularly during complex sensory tasks, and provide direct evidence for the role of the DLPFC during postural control of a clinically relevant measure of balance.

History

Journal

Brain and behavior

Volume

8

Issue

10

Article number

e01109

Pagination

1 - 11

Publisher

Wiley

Location

Chichester, Eng.

eISSN

2162-3279

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2018, The Authors