How to design a NIBS study in the cognitive domain: Common pitfalls and recommendations

Noninvasive brain stimulation (NIBS) has significantly advanced our knowledge of how the brain enables us to perform cognitive operations. NIBS techniques are unique as they allow for experimentally manipulating neural activity in a specific brain network at a specific time point to systematically assess the consequence of such manipulations for task performance. To draw conclusive insights from NIBS studies, a carefully controlled design needs a variety of control conditions to ensure specificity of the observed effects. We discuss common pitfalls in designing NIBS studies and argue that adequate control strategies depend on the goals of a study and the intended claims. Well-controlled NIBS studies can contribute unique insight into brain-cognition relationships beyond functional neuroimaging. The combination of NIBS with imaging further allows testing and validating some assumptions made in behavioral NIBS studies, providing an avenue of network research into dynamic state-dependent cognitive brain circuits and their contribution to cognition.