Compelling evidence for the efficacy of theta-burst stimulation above the angular gyrus for reducing mind wandering propensity: A successful pre-registered study

Mind wandering (MW) is a common mental phenomenon where attention shifts spontaneously from an external task to internal trains of thought. Recent studies propose that non-invasive brain stimulation methods hold potential for influencing attentional shifts between on-task and MW states. Exploratory analysis from a recent repetitive transcranial magnetic stimulation (rTMS) study reported that targeting the left angular gyrus (AG) with inhibitory continuous theta-burst stimulation (cTBS) reduced MW compared to sham stimulation, without affecting executive performance (Drevland et al., 2024). The present study is a pre-registered, direct replication of the study by Drevland et al., but also expands their protocol by applying excitatory intermittent theta-burst stimulation (iTBS) targeting the same cortical area. Using a triple-blind crossover design, healthy participants completed four blocks of the Finger-Tapping Random Sequence Generation Task (FT-RSGT) in three sessions on separate days. Each session included three rounds of either real (cTBS or iTBS) or sham stimulation in an accelerated rTMS design. We successfully replicated the effect of cTBS in reducing MW propensity but failed to find the expected increase in MW post-iTBS stimulation. Furthermore, based on a joint analysis of the current data and that from Drevland et al., we found compelling evidence for cTBS being efficient both in reducing MW and improving executive performance. Our results provide evidence for the causal relationship between the left AG and shifts of attention during an executive task, highlighting the role of the default mode network in the generation and maintenance of MW episodes.