Cognitive Processes in Aging and Neurodegenerative Disorders Cognitive Processes in Aging and Neurodegenerative Disorders

    Changes in cognition are associated with aging and with neurodegenerative disorders, such as Alzheimer’s disease (AD). Our work is focused on understanding the cognitive and brain changes associated with aging and those that characterize the most common neurodegenerative disorders (particularly AD), so that this information can be used to improve diagnosis and treatment of older persons. We have demonstrated that the cognitive hallmark of AD is a dramatic impairment in new learning (i.e., episodic memory) and the rapidity with which new information is lost over a delay. We have shown that this episodic memory loss is associated with abnormalities in medial temporal lobe structures, particularly the entorhinal cortex and the hippocampus. These brain regions undergo selective neuronal loss in the earliest stages of AD, and we have used structural MRI, functional MRI, and SPECT scans to assess the structural and functional alterations in these, and other, brain regions during the evolution of AD.  We have shown that these measures taken alone, or in combination, can be used to predict which individuals with mild memory problems are likely to progress to established AD. We have also examined the genetic markers associated with cognitive performance among older individuals with normal cognition and those in the prodromal phase of AD.  In addition, we have identified the factors associated with maintenance of cognition over time in older persons.