This auditory event-related potential (ERP) study investigated a candidate neurophysiological marker of Alzheimers disease (AD) and symptom severity. ERPs are sensitive to disruption of cortical processing and therefore have been used to study cortical effects of AD. The P50 ERP component has been shown to increase in amplitude with healthy aging, with multiple-domain relative to single-domain mild cognitive impairment (MCI), and in MCI patients who convert to AD compared to those whose diagnoses remain stable. As “MCI due to AD” has recently been defined as the symptomatic predementia phase of AD, P50 amplitude may reflect changes underlying AD progression in the earliest stages and is expected to vary as a function of cognitive impairment. There is also evidence to support P50 amplitude decrease in AD compared to MCI patients and conflict in the literature as to whether P50 is larger in AD relative to age-matched controls. This study explores P50 amplitude as a marker to distinguish mild AD patients from healthy older controls as well as the relationship between P50 amplitude and symptom severity, as measured by the Mini Mental Status Exam (MMSE).M.S., Clinical Psychology -- Drexel University, 201
