Patterns of Brain Activity Supporting Autobiographical Memory, Prospection, and Theory of Mind, and Their Relationship to the Default Mode Network

A core brain network called the default mode network (DMN) supports three distinct self-referential processes: remembering the past, imagining the future, and understanding others' minds. Functional MRI scans revealed a common pattern of neural activation across all three processes within the DMN. Autobiographical remembering and prospection more strongly engaged midline DMN structures, while theory-of-mind reasoning more strongly engaged lateral DMN areas. Activity in a key DMN node, the medial prefrontal cortex, correlated with activity in other DMN regions during all three tasks. The findings suggest the DMN provides a shared neural foundation for simulating internal experiences.

Study at a glance

Abstract

The ability to rise above the present environment and reflect upon the past, the future, and the minds of others is a fundamentally defining human feature. It has been proposed that these three self-referential processes involve a highly interconnected core set of brain structures known as the default mode network (DMN). The DMN appears to be active when individuals are engaged in stimulus-independent thought. This network is a likely candidate for supporting multiple processes, but this idea has not been tested directly. We used fMRI to examine brain activity during autobiographical remembering, prospection, and theory-of-mind reasoning. Using multivariate analyses, we found a common pattern of neural activation underlying all three processes in the DMN. In addition, autobiographical remembering and prospection engaged midline DMN structures to a greater degree and theory-of-mind reasoning engaged lateral DMN areas. A functional connectivity analysis revealed that activity of a critical node in the DMN, medial prefrontal cortex, was correlated with activity in other regions in the DMN during all three tasks. We conclude that the DMN supports common aspects of these cognitive behaviors involved in simulating an internalized experience.