An article posted January 22nd on masshightech.com:
Some researchers at MIT believe that schizophrenia may be triggered by over-stimulating the brain system that handles self-reflection processes.
This past week, researchers at the MIT McGovern Institute for Brain Research made public their findings. Historically, they claimed, schizophrenia — characterized as a series of disturbed thoughts, perceptions and emotions — is believed to be caused by disconnections among the individual brain regions that control the various cognitive and other processes.
However, they found that schizophrenia is also associated with an excess of communication between the so-called default brain regions. These default regions handle self-reflection processes and activate when a person is either contemplating himself or herself or nothing in particular. This default network includes the medial prefrontal cortex and the posterior cingulate cortex — brain portions associated with self-reflection and autobiographical memory recall processes.
People usually suppress the brain default system when performing challenging tasks, stated John Gabrieli, an MIT professor and one of the study’s authors. The researchers found that patients with schizophrenia don’t have the typical brain default suppression capabilities, however. Ultimately, this realization may help to explain schizophrenia’s cognitive and psychological symptoms. The hyperactive default system may account for schizophrenic hallucinations and paranoia. For instance, point out the researchers, if a brain region, whose activity normally handles the self-focus process, is active while the patient is listening to a voice on television, the patient may perceive erroneously the voice is directed at them specifically.
To conduct its study, the team selected three carefully matched groups of 13 subjects each: schizophrenia patients; non-psychotic first-degree relatives of patients; and healthy controls. The subjects were scanned by functional magnetic resonance imaging during rest or while performing easy or hard memory tasks.
Gabrieli explained that future research may lead to ways of predicting or monitoring individual patients’ response to treatments for schizophrenia, which afflicts about one percent of the population.
Also see:
Altered brain activity in schizophrenia may cause exaggerated focus on self: MIT study links schizophrenia to key 'default mode' brain system
Hyperactivity and hyperconnectivity of the default network in schizophrenia and in first-degree relatives of persons with schizophrenia
Graphic courtesy Susan Whitfield-Gabrieli, McGovern Institute for Brain Research at MIT.
