Self-referential encoding in the developing brain

Episodic memory is closely linked to the self and information related to the self tends to be better remembered. In adults, the brain's default mode network (DMN) supports self-referential thought and memory, with the medial prefrontal cortex (mPFC) being important for both functions. How the DMN supports self-referential encoding in children, and where in the mPFC the processes of self-referencing and episodic memory interact, is unknown. We investigated the neural development of self-referential encoding in 83 participants ages 7-25. While undergoing MRI, participants viewed objects and answered self-referential or semantic questions. Self-referential compared to semantic encoding resulted in better recollection across all ages. Self-referential encoding was associated with greater activation across the DMN and inferior frontal gyrus (IFG), with age-related increases in the dorsal mPFC and left IFG. Region-of-interest analyses revealed the interaction of self-referential episodic memory in the anterior mPFC and left hippocampus. The dorsal and anterior mPFC showed a counteraction effect of self-related thinking with the previously demonstrated age-related increase in DMN deactivation for subsequent memory encoding. These results suggest that self-referential facilitation matures and interacts with the episodic memory system in the brain to support the development of episodic memory from childhood to adulthood.