Another theme in our research program has been the neuroscience of executive processing and working memory. This work started with our early observation of brain activation in human prefrontal cortex in the context of spatial and object working memory. More recently, we have become interested in the way that task-irrelevant stressors (such as emotionally salient pictures, or the unpredictable delivery of mild foot shock) influences functional connectivity between the amygdala, inferior frontal gyrus, and ventromedial prefrontal cortex when subjects are engaged in demanding primary tasks such as working memory or maze finding. Our studies have provided support for our hypothesis that the inferior frontal gyrus regulates stress-evoked activity in the amygdala to help protect performance on primary tasks.
In collaboration with Dr. Naomi Driesen and Dr. John Krystal’s research group in Yale’s Department of Psychiatry, we have begun to investigate the role of NMDA receptors in prefrontal cortex during working memory tasks using ketamine challenges. These studies have demonstrated that ketamine infusion reduces activation in the dorsolateral prefrontal cortex and causes a concomitant reduction in working memory performance.
Sample publications
Dolcos F, McCarthy G (2006) Brain systems mediating cognitive interference by emotional distraction. J Neurosci 26:2072-2079.
Driesen NR, McCarthy G, Bhagwagar Z, Bloch MH, Calhoun VD, D'Souza DC, Gueorguieva R, He G, Leung HC, Ramani R, Anticevic A, Suckow RF, Morgan PT, Krystal JH (2013) The Impact of NMDA Receptor Blockade on Human Working Memory-Related Prefrontal Function and Connectivity. Neuropsychopharmacology.
Gold, AL, Morey, RA, McCarthy, G Amygdala-ventral prefrontal cortex functional connectivity during threat-induced anxiety and goal-distraction (under review)