Individualised Alpha Neurofeedback in Left Versus Right Motor Strip: Learning Phenomenology and Functional Neural Networks

Abstract

<p>Neurofeedback is a process where neural oscillations are trained to be self-regulated through a process of operant conditioning. In order to effectively validate neurofeedback’s use as an intervention a better understanding of the neural mechanisms that underlie the learning effects of neurofeedback training, and whether they can be effectively enhanced, is needed. The purpose of this thesis was to learn if individualised alpha neurofeedback can effectively enhance alpha over sensorimotor regions, and whether this improved attentional performance (using the Attention Network Test). Importantly, cortical generators for neurofeedback training were expected to be hemisphere specific, thus hemispheric differences were compared by using two intervention groups (C3/C4), with neurofeedback being applied to either the left or right hemisphere. Source localisation (using eLORETA) was used to identify change in attentional network loci following alpha neurofeedback training. Phenomenological change in conscious experience during neurofeedback was also evaluated over the length of neurofeedback training (using the PCI and DAQ). This thesis contains a comprehensive literature review, three research studies, followed by an overall conclusion. Results were drawn from over 600 hours of pre-processed data that was collected from 27 participants, over the course of 12 Neurofeedback Training Sessions. Findings indicated that alpha activity was enhanced across neurofeedback, both within and across sessions, by alpha neurofeedback applied at the right C4 site. No change in the trained alpha band was observed after training at C3. Orienting of attention, also appeared to improve only after training at C4. Source localisation revealed hemisphere specific changes, identifying right BA40, the inferior parietal lobe, as the most prominent source of enhanced alpha activity. Other areas with significant alpha enhancement voxels were Right BA2 and BA3 (postcentral gyrus), BA13 (insula), and BA39 (angular gyrus). This change was likely reflecting both baseline and functional change within the salience network. The DAQ subscale, Vigilance, was shown to decline significantly across neurofeedback training at C4. Multiple variables on the PCI and DAQ showed large effect sizes in linear trends but were not significant. Results indicated that DAQVigilance decreases during NFBT were significantly associated with decreased activity in the inhibited 15-30Hz band located in right BA9. Overall results indicate the efficaciousness of alpha neurofeedback training and support use of diverse measures to evaluate change.</p>