Tonya Bennett, Student, School of Psychology; Whillma Quenicka, Student, School of Psychology; Keith McGoldrick, Student, School of Psychology; Henry Soper, Faculty, School of Psychology
Objectives. Do age trajectories of neuropsychological functioning differ for those at, above, and below the average level of functioning? The Average Impairment Rating (AIR) was evaluated to see overall neuropsychological impairment, and then tests of Verbal Skills tests were similarly evaluated.
Methods. To track the trajectory of neuropsychological functioning, data were drawn from a popular comprehensive set of normative data for the Expanded Halstead-Reitan battery. Norms for 12 years of education were used for average (t=50) and low (t=37) functioning groups, while those for 16 years of education were used for high functioning (t=63). Normative data for the AIR, the Aphasia Screening Test, the Boston Naming Test, and the Boston Diagnostic Ideation Material (BDAE) were used and compared to those of the 20-34 year group.
Results. The AIR declined linearly so that by age 65 the performance had dropped two SD and three by age 80 regardless of functioning group. The performance on the Aphasia Screening Test and the BDAE showed no decline through age 80. Performance on the Boston Naming Test shows a decline of approximately 1 SD by age 65, but then a continued decline for average and low functioning groups, but not for the high functioning one.
Conclusions. Parallel trajectories for all levels of functioning were found for all tests to age 65. A uniform decline in the AIR was found across all functioning levels. However, not all verbal tasks showed such decline, which may have to do with crystalline abilities needed, which hold better than others.