On the role of prefrontal and parietal cortices in mind wandering and dynamic thought

Poster Session A - Saturday, April 13, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

Tara Rasmussen¹ (t.rasmussen@uq.net.au), Hannah Filmer², Paul Dux³; ¹The University of Queensland

Mind wandering is a prevalent phenomenon in everyday life and can have both adaptive and detrimental effects on many cognitive functions. Self-reported task unrelated thought is the most common operationalisation of mind wandering. However, a dynamic framework has recently been proposed to characterise the heterogeneity of internal thoughts, suggesting there are three distinct thought types – freely moving thought, deliberately constrained thought, and automatically constrained thought. While previous research applying transcranial direct current stimulation (tDCS) has causally implicated the prefrontal cortex and inferior parietal lobule in mind wandering, there is currently very little evidence on how the dynamic thought types are causally represented in the brain. To that end, the current large scale registered report applied anodal high definition tDCS (HD-tDCS) to the left prefrontal, right inferior parietal, and occipital cortices to investigate the causal neural substrates of the dynamic thought types, in 228 individuals. This research utilised a behavioural task designed to measure periods of internal thought and changes in executive functioning, alongside four dynamic thought probes presented throughout the task. The findings suggest stimulation did not modulate overall reporting of task unrelated thought. However, freely moving thought was reduced after prefrontal cortex stimulation, relative to sham stimulation. Furthermore, deliberately constrained, or goal orientated, thoughts were found to be reduced following parietal stimulation, relative to sham stimulation. Collectively, these findings provide evidence of anodal HD-tDCS affecting the frequency of the dynamic thought types, with distinct effects across different brain regions for freely moving and deliberately constrained thoughts.

Topic Area: ATTENTION: Other