Composite images document brain tissue loss (blue) and expansion of the fluid-filled ventricles (red) that swell to fill the space over one year. Degeneration accelerates as individuals develop mild cognitive impairment (MCI), an intermediate stage between health and
dementia. Images 1 through 3 show composite normal, MCI, and AD brains. Image 4 reveals the difference in tissue loss between MCI and normal; image 5 depicts the difference between AD and MCI, and 6 contrasts an AD brain with healthy normal tissue. Opposite: A schematic of the brain shown on this page. The temporal lobes, associated with memory and cognition, are in green.