Electroencephalographic correlates of continuous postural tasks of increasing difficulty

Publication date: Available online 1 November 2018Source: NeuroscienceAuthor(s): Amy E Edwards, Onur Guven, Michael D Furman, Qadeer Arshad, Adolfo M BronsteinAbstractCortical involvement in postural control is well recognised, however the role of non-visual afferents remains unclear. Parietal cortical areas are strongly implicated in vestibulo-spatial functions, but topographical localisation during balance tasks remains limited. Here, we use electroencephalography (EEG) during continuous balance tasks of increasing difficulty at single electrode positions. Twenty-four healthy, right-handed individuals performed four balance tasks of increasing difficulty (bipedal and unipedal) and a seated control condition with eyes closed. Subjective ratings of task difficulty were obtained. EEG was recorded from 32 electrodes; 5 overlying sensory and motor regions of interest (ROIs) were chosen for further investigation: C3, Cz, C4, P3, P4. Spectral power and coherence during balance tasks were analysed in theta (4-8Hz) and alpha (8-12Hz) bands. Alpha power reduced as task difficulty increased and this reduction correlated with subjective difficulty ratings. Alpha coherence increased with task difficulty between C3-Cz-C4 electrode pairs. Differential changes in power were observed in Cz, suggestive of a distinct role at this electrode location, which captures lower limb cortical representation. Hemispheric asymmetry was observed, as reflected by greater reductions in theta and alpha powe...
Source: Neuroscience - Category: Neuroscience Source Type: research