Extensive neuroimaging research has identified a set of brain regions with prominent activity during ?no task? baseline conditions, collectively known as the default mode network. The DMN is hypothesized to drive a variety of functions including future planning, predictions of outcome, retrieval of autobiographical memories and integration of external information, suggesting its central importance in healthy and adaptive brain activity dynamics. Under the supervision of Dr. E. Stamatakis and Prof. D. Menon, the specific aim of my PhD is to decipher the exact functional role of this network in human cognitive processing, using functional magnetic resonance imaging (MRI). This in turn may allow us to improve biomarkers in detecting the severity of impairment, predict cognitive outcomes and propose potential therapeutic agents in mental disease states.