At a recent meeting, neurologists described resting-state connectivity of brain regions associated with introspection. This network is chronically hyperactivated and hyperconnected in patients with schizophrenia. When healthy people are at rest, parts of the frontal lobes are not correlated, but in patients with schizophrenia and bipolar disorder, they are linked. This may help explain cognitive dysfunction in both disorders.
Michael Greicius, MD also addressed the default-mode network of the brain during his talk on Alzheimer's disease. The posterior regions of the default-mode network tend to overlap considerably with brain regions that show reduced metabolism in the earliest stages of Alzheimer's disease. “Using these functional connectivity approaches, our group and others have demonstrated reduced functional connectivity in the default-mode network in Alzheimer's disease, mild cognitive impairment, healthy older controls with prominent amyloid plaque burden, and healthy older carriers of the ApoE4 allele,” he said. In addition to functional changes, this brain network also appears to undergo structural changes and overlap with maps of amyloid plaque distribution (amyloid causes brain cell death in Alzheimer’s Disease).
Classically, neurologists study and describe brain anatomy whereas psychiatrists are concerned with human behavior. As new brain imaging techniques become more robust, the distinction between these fields of medicine blur.