EEG alpha rhythm modulation using sham neurofeedback during attentional control in a virtual reality environment: a Registered Report

Neurofeedback provides real-time information about brain activity to induce targeted modulation of neural rhythms. A central assumption of neurofeedback is that the motivational or penalizing valence of feedback acts as a contingent signal capable of modulating brain activity. However, robust neurophysiological evidence supporting this mechanism remains limited. To address this gap, we developed a Virtual Reality (VR) sham neurofeedback system enabling controlled manipulation of feedback valence and evaluation of its effects on EEG alpha rhythm modulation during an attentional task. This study protocol was pre-registered and evaluated before data collection as a Registered report. In a within-subject design, 36 healthy adults, balanced by sex and stratified by age completed positive and negative valence sham neurofeedback conditions and a no-feedback control condition. Continuous EEG was recorded to derive relative alpha power (αrel) over temporo-parietal regions, a marker of increased neural resource allocation. Effects of condition on αrel were assessed using a linear mixed-effects model. Our results showed that αrel decreased significantly during both positive and negative sham neurofeedback compared with the no-feedback control, with no significant difference between positive and negative sham neurofeedback conditions. These findings indicate that feedback valence alone, independent of closed-loop contingency, is sufficient to induce temporo-parietal alpha modulation.