The degree of conation on neuropsychological tests does not account for performance invalidity among litigants.

Conation has been defined as the ability to focus and maintain intellectual energy over time. Prior research has shown that conation contributes to the magnitude of differences in test scores among brain-damaged and non-brain-damaged examinees. The purpose of the current investigation was to determine if conation might similarly account for differences in test scores among performance valid and performance invalid examinees. An archival analysis was therefore carried out on 52 examinees administered the Halstead-Reitan Neuropsychological Battery (HRNB) and several performance validity tests in a medico-legal context. Analyses revealed that conation had no impact on the magnitude of test score differences between groups and that performance invalid examinees scored worse than performance valid examinees on all but one test of the HRNB. These results support the idea that the identification of performance invalidity calls into question the reliability and the validity of all test score interpretations in an evaluation, even those with less conative load.