On the basis of their data, the researchers are proposing a new hypothesis that suggests that Alzheimer’s disease may be due to abnormalities in the regions of the brain that operate the “default state.” This is the term used to describe the cognitive state people defer to when musing, daydreaming, or thinking to themselves.
The study involved the use of five different medical imaging techniques to study the brain activity of 764 people, including those with Alzheimer’s disease, those on the brink of dementia, and healthy individuals.
The investigators observed that the regions of the brain that were active when participants slipped into comfortable patterns of thought are the same as those that, later in life, exhibit the disabling clumps of plaque characteristic of Alzheimer’s.
The researchers postulate that it may be the default activity in the brain that augments a metabolic cascade eventually precipitating the onset of Alzheimer’s disease years later. This finding could be useful to scientists and clinicians working to identify and understand the beginnings of the disease.