There are three important strands to our work with patients with GSP and GAD: The first of these strands is determining the degree to which the pathology seen in GAD differs from that seen in GSP. In previous work, we were the first to demonstrate that patients with GSP and GAD differ in their responsiveness to emotional expression stimuli. Specifically, we showed that the heightened amygdala response to fearful expressions seen in GSP is not seen in patients with GAD. Indeed, they show indications of hypo-responsiveness. Over the past year, we have extended these results in two important ways: (a) In the first developmental study of its kind, we have demonstrated that the heightened response to fearful expressions seen in GAD is present early in life and is not modulated by neural changes in the development of systems mediating face processing;and (b) We have also demonstrated, for the first time, that patients with GSP and GAD share a common deficit in the recruitment of systems involved in top down attention. This deficit results in heightened processing of emotional distracters and thus, presumably, increases the risk of the development of these disorders in affected individuals. The second strand concerns the specific nature of the functional impairment seen in GSP. In previous work, we have shown that GSP does not simply represent a heightened amygdala response to social threats. Instead, there appears additionally to be atypical self referential processing of social information. In short, our earlier work had indicated an important role for not only the amygdala but also medial prefrontal cortex (MPFC a region critical for self referential processing) in GSP. This year, we extended this work by showing highly atypical processing of social interactional vignettes in patients with GSP. Specifically, while healthy participants show heightened recruitment of MPFC when processing social transgressions (intentional spitting out unpalatable food at dinner table), patients with GSP show heightened recruitment of this region when processing social accidents (unintentionally spitting out food when choking). Importantly, the emotion most associated with social accidents is embarrassment. An important symptom shown by patients with GSP is a heightened level of embarrassment. The third strand of work concerns the specific nature of the functional impairment seen in GAD. In particular, we have been examining whether some of the problems in emotional responding in GAD that we observed in our preliminary work with patients with this disorder might manifest in difficulties on decision making tasks. Following on from our previous results, we have further demonstrated that patients with GAD show significant impairment when performing reward/ punishment based decision making tasks. Notably, such impairments were not seen in patients with GSP. Our on-going work is following up these results and using functional magnetic resonance imagingto determine their neural basis.
