30 Years of Brain Stimulation Studies on Cognition and Consciousness - Where We Stand and Future Directions for Basic and Clinical Research

It is almost 30 years since the publication of Amassian’s seminal work pioneering the use of noninvasive brain stimulation for studying human cognition and consciousness. Ever since this elegantly designed study, the field has grown immensely, with a wide range of cognitive domains being investigated using this technique. From a methodological perspective, the field has seen much refinement of paradigms and protocols, as well as the combination of brain stimulation with neuroimaging techniques. Moreover, computational modelling approaches have been implemented to further conceptualize the mechanistic understanding of the induced effects. However, despite all of these advances, some fundamental challenges remain unsolved. For example, we still lack a clear mechanistic understanding of how brain stimulation modulates perception, behaviour, and the underlying physiology. Furthermore, there has been much debate in recent years on the strength, consistency, and reliability of some of the effects reported in the literature. Among the others, addressing the reproducibility of significant findings as well as understanding the potential relevance of so-called null results have become issues of increasing importance.

The aim of this Research Topic is to generate an open discussion on the contribution of brain stimulation to the study of cognition and its future directions. We will welcome articles which examine the current state of the field and its future challenges, such as: What has brain stimulation contributed to the study of human cognition and consciousness, including their disorders (such as blindsight and neglect)? What are our major challenges and caveats? Are the described effects sufficiently robust, reliable, and reproducible? How can the field move forward? Is there still mileage in the conventional approaches? Developing novel approaches is the way forward to increase the mechanistic understanding of brain stimulation effects? Where is the future of brain stimulation in the study of human cognition and in the clinic for the next 30 years?

Brief commentaries expressing authoritative views on these issues, a lengthier review and submissions with empirical data, including replications and null results are welcome.