monitoring (Goldstein et al., 2009), and maladaptive decision-making (Paulus et al., 2007) in drug addicts. Naqvi and Bechara (2010) have elucidated a rather thorough model of insula’s interoceptive role at multiple stages of the addiction cycle (e.g., drug-taking, -withdrawal, -urges). Of particular note, during acute abstinence, the insula is theorized to track homeostatically relevant withdrawal-induced bodily changes and in turn interact with other regions (e.g, vmPFC, amygdala and striatum), thereby altering affective (e.g., anxiety, irritability) and motivational (e.g., cue reactivity, smoking urges) states (Naqvi and Bechara, 2010). To this list we suggest adding attentional states, hypothesizing that increased withdrawal-related insula engagement during abstinence interferes with normal network switching processes and perhaps underlies the breakdown in negative coupling between the DMN and ECN. That is to say, during periods of abstinence the most homeostatically relevant stimuli are often internal bodily sensations subjectively experienced as withdrawal symptoms, which result in objectively manifest decreased behavioral performance due to a shift in activity towards DMN and away from ECN.
