Mind wandering is a mental phenomenon we humans experience on a daily basis. Yet, we still lack a complete understanding of this pervasive mental state. Over the past decade, there has been an increase in publications regarding mind wandering and non-invasive brain stimulation using transcranial direct current stimulation, a versatile tool that can modulate neuronal excitability and potentially lead to changes in cognition. Results from this line of research are painting a picture of disagreement within the scientific community. While some researchers claim to successfully modulate mind wandering using tDCS, others report problems replicating these findings. Currently, a satisfactory conclusion is lacking, a situation which calls for more accurate and focal stimulation techniques as well as high-powered, registered reports within the topic. Recently, a study reported successfully reducing mind wandering using a more focal stimulation technique, high-definition tDCS (HD-tDCS) over the dorsolateral prefrontal cortex in adult humans (Boayue et al., 2020). However, this study was not pre-registered and only provides preliminary evidence on the efficacy of HD-tDCS in interfering with mind wandering. The current study aims to replicate the effect found by Boayue et al. (2020), with a high-powered, pre-registered study protocol. Furthermore, we aim at extending the study by investigating whether the effects of HD-tDCS on mind wandering are prolonged, accompanied by changes in tonic and phasic pupillary responses, and neurophysiological responses associated with sensory prediction errors (the mismatch negativity), executive control (frontal midline theta oscillations) and attention (posterior alpha activity).
The effect of transcranial direct current stimulation on the interplay between executive control, behavioral variability and mind wandering: A registered report