Passive Listening and Task Related P300 Measurement for the Evaluation of Dementia and Pseudodementia

The late evoked potential P300 was tested in three groups of subjects. These consisted of 25 patients suffering from dementia (Group I ), 14 patients suffering from pseudodementia due to severe depressive disease (Group It ), and 24 age-matched normal controls (Group Ill). Since patients suffering from dementia frequently have difficulties in counting targets in the “oddball” paradigm, we evaluated the usefulness of a Passive Listening condition. With the classical “oddball” paradigm, 78% of the subjects were correctly related to one of the three groups examined. The “P300-like” wave form produced in the Passive Listening condition was not found to be sensitive enough to allow such a distinction.