Identification of Early Markers of Alzheimer's Disease by Using Eye Tracking in Reading.

The objective of this study is to identify early and accurate semantics markers of Alzheimer's disease (AD) by using two types of methods. First, the investigator will evaluate semantic processing of patients with AD or related disorders which will be compared to age matched controls by taking neuropsychological tests. Then, the investigator will analyze the effect of contextual word predictability on eye movements in reading sentences with the help of the same participants by using an eye tracker. Both of these methods will be used twice with a time interval of 6 months.