The role of right anterior insula and salience processing in inhibitory control.

Editor's Note: These short, critical reviews of recent papers in the Journal, written exclusively by graduate students or postdoctoral fellows, are intended to summarize the important findings of the paper and provide additional insight and commentary. For more information on the format and purpose of the Journal Club, please see Review of Cai et al. Understanding the functional organization of the brain in inhibitory control has been a challenge for cognitive neuroscien-tists for more than a decade. In its simplest form, such as outright inhibition in response to a Stop signal after the intended movement plan is initiated, high-level processing in the prefrontal cortex presumably generates a stopping command to cancel the plan before execution. Many studies investigating the functional organization of prefrontal regions during inhibition have agreed upon the right inferior frontal cortex (rIFC) as the most critical region for recruiting inhibition (Aron et al., 2014). In contrast, less is known about the role of the coactivated region in the right anterior insula (rAI), where activation was even more prominent (see meta-analysis by Swick et al., 2011). Several views have emerged to explain the functions of rAI in cognitive task sets, including tasks that address inhibition. Some propose that the rAI maintains task rules, represented by its sustained activity throughout task performance (Dosen-bach et al., 2008). Alternatively, rAI may maintain attention and focus during the task (Nelson et al., 2010). Neither of these accounts considers a specific role for rAI in inhibitory control. A third, more compelling view, takes into account the well established role of rAI in interceptive awareness and processing of salient events (Craig, 2009; Uddin, 2015). According to this account, rAI, embedded in the sa-lience network, detects salient events and coordinates other brain networks, such as central-executive networks, to guide behavior. The results of a recent study by Cai and colleagues (2014) are consistent with this account. Cai and colleagues (2014) reported not only that rAI plays a different role from rIFC in inhibitory control, but that it is embedded in the salience network that is functionally dissociated from rIFC and its interconnected network. Distinguishing the roles of rAI and rIFC during inhibitory control is challenging because they are coactivated in many neuroimaging studies on inhibition. Cai and colleagues (2014) used novel multi-stepped quantitative approaches to reveal the functional segregation between rAI and rIFC. The study used multiple da-tasets: one resting state (n ϭ 21), and …