Objective assessment in dementia: automated psychometric tests and the P3

Event-related potentials have been shown to be closely correlated with cognitive functioning and it has been suggested that one such potential, the P3, can act as an objective and sensitive measure of the degree of dementia. The P3 is no longer thought of as a diagnostic tool in dementia; however, longitudinal changes in the P3 latency can be used to follow the course of a dementing illness or to assess effects of therapy. It is possible that the measurement of P3 latency may prove useful in the selection of patients with early dementia. Automated psychometric tests are also of considerable value in assessing large numbers of cognitively impaired subjects. The advantages of using these tests and their usefulness in multicentre drug trials is discussed.