Scaffolding imagination: A role for medial frontal cortex in the expression of off-task thought

Abstract

We often think about people, places and events that are outside of our immediate environment. Although prior studies have explored how we can reduce the occurrence of these experiences, the neurocognitive process through which they are produced are less understood. The current study builds on developmental and evolutionary evidence that language helps organise and express our thoughts. Behaviorally, we found the occurrence of task unrelated thought (TUT) in easy situations was associated with thinking in words. Using experience sampling data, in combination with online measures of neural function, we established that activity in a region of anterior cingulate cortex / medial-prefrontal cortex (mPFC) tracked with changes in the expression of TUT. This region is at the intersection of two mPFC clusters identified through their association with variation in aspects of spontaneous thought: thinking in words (dorsal) and mental time travel (ventral). Finally, using meta-analytic decoding we confirmed the dorsal/ventral distinction within mPFC corresponding to a functional difference between domains linked to language and meaning and those linked to memory and scene construction. This evidence suggests a role for mPFC in the expression of TUT that may emerge from interactions with distributed neural signals reflecting processes such as language and memory.All rights reserved. No reuse allowed without permission.(which was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.The copyright holder for this preprint . http://dx.doi.org/10.1101/153973 doi: bioRxiv preprint first posted online Jun. 22, 2017; Scaffolding imagination 3 Main bodyWe spend upwards of one third of our daily lives engaged in thoughts and feelings related to events taking place in imagination rather than the here-and-now [1][2][3]. Although aspects of these experiences have beneficial associations with creativity [4], planning the future [5] and the reduction of psycho-social stress [6], their occurrence has also been linked to absent-minded error [7] and unhappiness [1,2]. Consequently, the ability to organise self-generated thoughts is an important element of adaptive cognition [8].Contemporary psychological theory has explored different mechanisms through which we influence spontaneous off task thoughts (for reviews see [9,10]). One line of evidence suggests that mechanisms of executive control help supress task unrelated thoughts (TUT) allowing better focus on the task in hand when needed. This hypothesis is based on evidence that measures such as fluid intelligence [11] and attentional control [12,13] are linked to reductions in the occurrence of TUT, especially in highly demanding externally-oriented tasks. Other studies have explored how we improve task focus through mental training or instruction [14][15][16].Although these data explain how we maintain focus on external tasks, they do not make clear those processes that facilitate the expression of thoughts unrelated to ...