These days, the number of dementia patients are growing along with the aging population. The NTHU Center for Cognition and Mind Sciences is currently enrolling subjects for MRI scan, to find out the differences of brain activity between young and old people when comprehending a sentence. Futhermore, with 2-3 years of continuous tracking of old people, we can clarify the connections between memory performance and brain activity. In total, 2 memory tests and 3 scans will be carried out in order to provide the best service possible for the subjects.