Losing your self

Social cognition has been related to the frontal lobes, namely frontomedian regions. This peculiar human ability requires the prediction of mental states and behavior of others, known as “theory of mind” or “mentalizing”. Moreover, self-monitoring, processing/evaluation of internal mental states, perception of pain and emotions, and sustaining personality and self have been associated with frontomedian regions. One dementia syndrome, frontotemporal dementia, is characterized by deep alterations in behavior and personality. We aim to isolate its neural correlates by systematic and quantitative meta-analyses of imaging studies and by investigating MRI and FDG-PET data in our own patient cohort. Indeed, we have been able to demonstrate that frontotemporal dementia specifically affects frontomedian neural networks related to social cognition. Moreover, we dissociated its neural substrates from the substrates of the other two subtypes of frontotemporal lobar degeneration, semantic dementia and progressive non-fluent aphasia, involving mainly language disturbances. Future studies will investigate the neural correlates of executive functions and behavioral deficits in these disorders using MRI and FDG-PET. The project contributes to the placement of the disease in a framework of cognitive neuropsychiatry and may suggest new approaches for therapy. Another frequent disorder is also characterized by alterations of the frontal lobes: Traumatic brain injury. Recently, it was suggested that long term outcomes mainly depend on social cognition. Accordingly, we investigated frontomedian alterations in this disease, namely diffuse axonal injury. We were able to show specific deficits such as inhibition of imitative response tendencies and evaluative judgements in frontomedian tasks using fMRI.