The effect of age and personality on the main cognitive processes in drivers

The purpose of this study is the evaluation of how the decline of cognitive abilities caused by aging is moderated by biologically determined personality dimensions: Neuroticism (N) and Extraversion (E). The research was conducted with the participation of 160 men in good physical health, professional drivers, aged 20-70 (Mean = 40, SD = 11). Personality traits were measured using Eysenck's Personality Questionnaire - Revised (EPQ-R), while Ravens Progressive Matrices, Go/noGo Task and Peripheral Perception Test were used to evaluate cognitive processes. The score of Ravens Progressive Matrices was treated as a control variable. The results of the study, based on a Hierarchical Multiple Regression Analysis, indicate that besides the intelligence level, age is the best predictor of cognitive functioning level and that this influence is additionally moderated by the N trait level as well as, less frequently, by the interaction of age and E. This means that high N trait level increases the influence of age on cognitive functions decline. When the N trait level was low, the age differences in measures of cognitive performance were not significant. Thus, the level of N trait may play an important role in the process of cognitive aging. The results are discussed in the context of a driving safety research.