Escaping the here and now: evidence for a role of the default mode network in perceptually decoupled thought.

Cognition that is not based on perception can lead to at least two different outcomes. In some situations, cognition that is independent of perception can allow actions to be selected other than those prescribed by immediate perceptual input. In others, cognition can be independent of perception and unrelated to the current behavioral goal allowing thoughts to develop that are largely independent of the actions involved in an external task. The default mode network (DMN) has been implicated in both of these kinds of perceptually decoupled thought. The current experiment used functional magnetic resonance imaging to explore whether a common region of this network was co-activated by both of these states. Both the medial pre-frontal cortex and the posterior cingulate - two major hubs of the DMN - showed greater activity when (i) actions that did not depend upon immediate perceptual input were faster and (ii) when actions based on perceptual input were slower. Together these data suggest that the DMN is important in cognition that is independent from perceptual input regardless of whether such thoughts result in action, or, instead compete with the behavioral goals of the moment.