Precision Targeting of Neural Networks with tDCS Informed by Brain Mapping

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that is gaining ground in the treatment of psychiatric and neurological disorders. The prevailing notion is that tDCS modulates regional neuronal activity in those regions, where the transcranially applied current in the brain is highest. Hence, the tDCS intervention should to be designed in a way that tDCS induces a sufficiently high electrical field strength in the targeted brain region. Although the tDCS-induced current intensity in the target region is critical, most tDCS studies are built on a one-size-fits-all approach: All participants receive a tDCS protocol, which is identical in terms of stimulation duration, intensity, and electrode placement. However, the spatial distribution of the electrical field in the brain is complex and varies greatly between individuals despite seemingly similar setup. This contributes substantially to the large interindividual variability of tDCS-induced after-effects on human brain function and hampers the use of tDCS as treatment intervention in neuropsychiatric disorders. In this chapter, we advocate for a personalization of tDCS-based targeting of brain networks and propose a precision tDCS approach that can account for interindividual variations in brain structure and function. We show that the intimate combination of tDCS and brain imaging is key for personalization of tDCS and showcase the potential of combined tDCS-neuroimaging for precision stimulation in scientific and therapeutic settings.