Brain scans allow researchers to monitor people's brain activity as they complete different tasks and to examine the links between brain function and disease. Researchers at the Massachusetts Institute of Technology used brain scans to investigate the links between schizophrenia and a network of brain structures called the default network. The default network is involved in self-reflection and autobiographical memories and tends to become active when we are not engaged in any particular task. The study gave brain scans to 39 people. 13 of them had schizophrenia, 13 of them were relatives of people with schizophrenia and 13 were healthy controls. The participants' brains were scanned while they were resting and while they undertook easy and hard memory tasks. In the participants with schizophrenia there were very strong and active connections in the default network while they were at rest and - unlike the healthy controls - they were unable to suppress the activity in this network as they worked on the memory tasks. The more active this network was and the less able people were to suppress it the worse they performed on the memory task and the worse were their symptoms. The default system was overactive, but to a much lesser extent, in the brains of the relatives of people with schizophrenia.
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