Music in the loop: an overview of current neurofeedback methodologies using music

How can music, a universal feature of human societies with the powerful ability to evoke meaningful emotions and influence mood, be used to control brain activity? Music therapy is a well-established discipline, but clinical neuroscience implications of its use remain to be established, in particular in the context of brain modulation. This literature review offers a comprehensive investigation into music-based neurofeedback studies, providing an overview of the underlying reasoning and methodological facets explored in previous music-based neurofeedback research. Through a critical assessment of the results obtained from thirteen studies, we delve into the methodologies and their limitations to propose potential hypotheses and approaches that could steer the development of innovative methodologies incorporating music-based neurofeedback. Our review is organized around three primary questions. Firstly, we address the question of why music is utilized as a stimulus instead of other alternatives, seeking to identify the primary motivations and any specific hypotheses on the use of music in these interventions. Secondly, we explore how music is integrated into the feedback loop, examining the various paradigms and stages of incorporating music as a central component. Lastly, we investigate the principal outcomes of the reviewed studies, aiming to identify the main findings and uncover potential neural correlates associated with the intervention. We found that most studies justify the choice of music as the neurofeedback interface given the link between music and emotion. The mechanistic explanation for the musical features used is generally absent, and there is no consensus regarding the imaging and/or behavioral success measure of NF. In sum, we discuss that when designing a music-NF study, one should consider the whole-brain neural correlates of music stimuli and their interaction with the target brain network and the reward mechanisms, to optimize the feedback intervention and test its specificity. This review intends to contribute as a valuable resource for researchers in the field, aiding in the development of a deeper understanding of music and neurofeedback and offering guidance for future investigations in this promising domain.