From the University of Parma press release via AlphaGalileo:
This elementary feature of schizophrenia is particularly disabling for those affected by the condition, say Italian scientists.
The study, published this week in Social Cognitive and Affective Neuroscience, and led by Vittorio Gallese, Professor of Physiology at the Dept. of Neuroscience of the University of Parma, used functional magnetic resonance imaging to study brain responses in first episode schizophrenic patients to social situations concerning the observation of bodily feelings experienced by other individuals.
This study revealed that, during such social perceptions, first episode schizophrenic patients showed differential neural activation with respect to healthy controls in brain regions also involved in the processing of one’s own body sensations.
One of these brain regions was the premotor cortex, underlying the integration of motor representations with information from the different senses.
Another brain region was the posterior insula, which is associated with the perception of bodily feelings, and plays a crucial role in distinguishing between self and other in affective social situations.
“These are important functions” – said Gallese – “as they allow the uniquely personal sense of one’s own experiences, including actions and sensations, known to be disturbed in schizophrenia. The observed neural alterations could be at the basis of a reduced ability both to distinguish others’ bodily experiences from one’s own experiences in social interactions and to intuitively understand the meaning of social situations”.
This new study demonstrates for the first time that in schizophrenia these functions appear to be altered when merely watching actions and sensations of other individuals.
“It is still poorly understood whether social dysfunction in schizophrenia specifically concerns the interrelationship with other individuals or whether it is primarily rooted in self-experience deficits”, said leading author Sjoerd Ebisch, post-doc researcher at the Department of Neuroscience and Imaging of the University of Chieti. “The results of this study start to shed light on the neural mechanisms of how self-experience deficits in schizophrenia pervade the social relationship with other individuals”.
According to Filippo Ferro, Emeritus Professor of Psychiatry at the University of Chieti and co-author of the study, “this study allows to investigate with an experimental paradigm the self-other distinction, a crucial problem in schizophrenic psychopathology”.
Another important result of the study is that neural activation in premotor cortex during the social perception task was negatively related to the severity of symptoms of subtle self-experience deficits in patients affected by schizophrenia.
“These specific symptoms remain stable during the entire disease progression, including the prodromal phase of schizophrenia. Therefore, the study of their relationship with brain function and social dysfunction is crucial from a clinical point of view”, explained Sjoerd Ebisch.
“Schizophrenia is characterized by different clinical and psychopathological aspects, and it is very important to identify the core features to better understand the disease and to establish a more accurate prevention strategy,” added Anatolia Salone, co-author of the study.
“The paper is unique” – said Georg Northoff, Professor of Psychiatry at the University of Ottawa Institute of Mental Health Research, Canada – “in that it investigates a very basic dimension of our experience and consciousness, namely the preverbal ability to integrate different sensory stimuli to the own self. Schizophrenic patients show abnormal changes in a particularly relevant region, the ventral premotor cortex, for linking own and others sensory stimuli to the own self while at the same time remaining connected to the environment. These unique findings suggest that the schizophrenic patients are indeed literally ‘out of touch with reality’ in that they remain unable to properly integrate their own self with others’ selves and thus the environment. This has not only important implications for our understanding of schizophrenia in particular but for the brain in general.”
“Freud hypothesised long ago that a blurred distinction between ‘me’ and ‘not me’ lies at the heart of psychotic thinking” – commented Prof. Mark Solms, Editor, of the Revised Standard Edition of the Complete Psychological Works of Sigmund Freud. “This important study places his theory on a new scientific footing, and identifies the brain mechanisms that mediate it. This is a major step forward.”