Researchers mainly looked at the participants' "association areas" of the brain
The subjects underwent an MRI that was focused on seven areas of the cerebral cortex of the brain. Most of these areas that were examined are often referred to as the “association areas.” The association areas are in charge of memory, judgement, and thought, just to name a few. However, they are not responsible for processing of sensory stimuli or movement. The thickness of these areas were measured because they tend to be the most affected in Alzheimer's disease. For the sake of comparison, seven other regions of the brain were measured as well, and the results of these tests showed an increased thickness in the cerebral cortex.