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

Attention is a vital process for selective focus on relevant information. Impaired attentional control is linked to disorders like depression and anxiety, often involving maladaptive strategies such as rumination. As a trainable skill, attentional control can be enhanced via learning, particularly when reinforced by feedback. Decreased EEG alpha power reflects cortical activation and neural resource allocation. While alpha-based neurofeedback typically uses closed-loop modulation, the impact of open-loop feedback remains unexplored. This study aimed to determine whether an open-loop feedback system could effectively modulate EEG alpha rhythms, as a correlate of increased neural resource allocation during the execution of attentional tasks. We conducted a within-subject experiment in which 36 healthy participants experienced positive and negative sham neurofeedback conditions, as well as a control condition with no feedback, all within a virtual reality environment. We hypothesized that relative EEG alpha power would decrease in the positive sham neurofeedback condition compared to the control condition, reflecting a meaningful increase in neural resource allocation. Data revealed that relative alpha power decreased during both sham neurofeedback conditions compared to the control condition (p = .002), with a greater reduction in the positive condition (p = .002) than in the negative condition (p = .03). These results demonstrate that neural oscillations are modulated when engaging in an attentional task reinforced by feedback, even when the feedback is not contingent with actual brain activity, and that this modulation depends on feedback valence.