Guest editorial: Special issue on noninvasive electromagnetic brain stimulation.

PMID: 23819143.

For several decades, electromagnetic brain stimulation for clinical applications has been investigated mainly with invasive techniques, such as deep brain stimulation (DBS), and this has limited its applicability. recent research has focused on transcranial magnetic stimulation (TMS) or electric current stimulation using direct current (DC), alternating current (AC), or more general current stimulation methods [i.e., generalized transcranial current stimulation (tCS)]. To explore the possibilities and limitations of these approaches, for a state-of-the-art assessment and looking into the future, we called for papers in the field and asked the authors to present new experimental and clinical findings on noninvasive transcranial electromagnetic brain stimulation. The submitted papers were subjected to a rigorous peer-review process, according to the IEEE Transactions on Neural Systems and Rehabilitation Engineering (TNSRE) guidelines, and the accepted papers form this special issue of TNSRE. After a general introductory article on the current state-of-the-art in the use of biophysical models and related technologies in tCS, the remaining articles are arranged in three main categories of topics: (1) specific modeling approaches for the study of noninvasive electromagnetic brain stimulation (2) techniques proposed for efficacy and reliability in transcranial magnetic stimulation (TMS) applications; and (3) specific applications of tCS and TMS in epilepsy, depression and brain-computer interfaces (BCI). We believe that this special issue, despite the relatively small number of papers, is a testament to the potential and promise that noninvasive electromagnetic brain stimulation presents for clinical and other applications. One may further comment that this issue reflects the promise of neuroengineering in general for effective applications in biomedicine.