Mirror images : neural correlates of emotion processing in autism, schizophrenia, and mental health

Imagine you see a woman biting into a sandwich, after which she grimaces and brings a hand to her mouth, gagging. A similar expression is likely to appear on your face, and you may even start to feel a bit nauseated. In this thesis we show that such entwining of emotion perception and experience is evident at the level of the brain: seeing others’ emotional facial expressions involves some of the same regions as experiencing the emotions yourself. Mirroring or simulating motor aspects in the so-called mirror neuron system (MNS) plays an important role in this process. In contrast to what was previously thought, we show that abnormalities in the MNS cannot explain the whole constellation of clinical features associated with autism. We do find that adults with autism improve in mirroring as they age, which could be related to slight concurrent improvements in social functioning. In addition to autism, schizophrenia is characterised by social deficits. We show that, while the social profile of schizophrenia sometimes resembles that of autism when negative symptoms (such as flat affect) are more pronounced, differences in their underlying neural profiles are predominant. The inclusion of studies on both autism and schizophrenia in this thesis increases our knowledge of possible neurobiological mechanisms underlying social dysfunction in general, as well as of these disorders specifically. These insights could provide important new directions for the development of more effective therapies.