Faculty Bibliography

Prior research links greater activation of posterior medial frontal cortex (pMFC) and anterior insula (AI) with decreasing outcome predictability during decision making, as measured by decreasing probability for the more likely outcome out of two or increasing outcome variance. In addition to predictability, much work indicates that the magnitude or 'stakes' of the outcome is also important. Despite the interest in the neural correlates of these decision variables, it is unknown whether pMFC and AI are differentially sensitive to predictability when magnitude is varied. This study examined brain activity during decision making in relation to decreasing outcome predictability for low as compared with high magnitude decisions. For low magnitude decisions, reduced predictability of the outcome was associated with greater activity in pMFC and bilateral AI, replicating prior studies. In contrast, there was no relationship between predictability and brain activity for high magnitude decisions, which tended to elicit greater pMFC and AI activity than low magnitude decisions for more predictable outcomes. These data indicate that the relationship between outcome predictability and pMFC and AI activity during decision making depends on magnitude, and suggest that these regions may be responding to the motivational salience of the decision rather than predictability information per se.

Over the past century, much research has investigated how the brain processes signals from the body (interoception) and how this processing may be disturbed in patients with psychiatric disorders. In this paper, I discuss the literature examining the relationship between interoceptive awareness and emotional and cognitive processes, and review the evidence suggesting that anxiety and obsessive-compulsive disorder (OCD) are characterized by abnormal interoception. A network of cortical and subcortical brain regions centered on the insula has repeatedly been implicated in interoception and is abnormal in anxiety and OCD. The investigation of interoception provides a framework for understanding behavioral and neural mechanisms of anxiety and OCD, although additional research is needed to directly link insula functioning to aberrant interoception in these disorders. Future work targeting interoception may be useful for the development of novel treatments.

Cognitive neuroscience investigates neural responses to cognitive and emotional probes, an approach that has yielded critical insights into the neurobiological mechanisms of psychiatric disorders. This article reviews some of the major findings from neuroimaging studies using a cognitive neuroscience approach to investigate obsessive-compulsive disorder (OCD). It evaluates the consistency of results and interprets findings within the context of OCD symptoms, and proposes a model of OCD involving inflexibility of internally focused cognition. Although further research is needed, this body of work probing cognitive-emotional processes in OCD has already shed considerable light on the underlying mechanisms of the disorder.

Neuromodulation shows increasing promise in the treatment of psychiatric disorders, particularly obsessive-compulsive disorder (OCD). Development of tools and techniques including deep brain stimulation, transcranial magnetic stimulation, and electroconvulsive therapy may yield additional options for patients who fail to respond to standard treatments. This article reviews the motivation for and use of these treatments in OCD. We begin with a brief description of the illness followed by discussion of the circuit models thought to underlie the disorder. These circuits provide targets for intervention. Basal ganglia and talamocortical pathophysiology, including cortico-striato-thalamo-cortical loops is a focus of this discussion. Neuroimaging findings and historical treatments that led to the use of neuromodulation for OCD are presented. We then present evidence from neuromodulation studies using deep brain stimulation, electroconvulsive therapy, and transcranial magnetic stimulation, with targets including nucleus accumbens, subthalamic nucleus inferior thalamic peduncle, dorsolateral prefrontal cortex, supplementary motor area, and orbitofrontal cortex. Finally, we explore potential future neuromodulation approaches that may further refine and improve treatment.