We investigated whether and how individual differences in personality determine cognitive training outcomes. Forty-seven participants were either trained on a single or on a dual n-back task for a period of 4 weeks. Fifty-two additional participants did not receive any training and served as a no-contact control group. We assessed neuroticism and conscientiousness as personality traits as well as performance in near and far transfer measures. The results indicated a significant interaction of neuroticism and intervention in terms of training efficacy. Whereas dual n-back training was more effective for participants low in neuroticism, single n-back training was more effective for participants high in neuroticism. Conscientiousness was associated with high training scores in the single n-back and improvement in near transfer measures, but lower far transfer performance, suggesting that subjects scoring high in this trait developed task-specific skills preventing generalizing effects. We conclude by proposing that individual differences in personality should be considered in future cognitive intervention studies to optimize the efficacy of training.
Cognitive training has become increasingly popular in research. Growing evidence suggests that training on working memory (WM) can lead to increased performance in non-trained tasks (for reviews, see e.g. Buschkuehl and Jaeggi, 2010 and Morrison and Chein, 2011). For example, we trained college students on either an adaptive single or dual n-back task, and as a result, both groups improved performance in non-trained matrix reasoning tasks to a comparable extent ( Jaeggi et al., 2010). However, we have repeatedly observed that some participants are positively challenged and demonstrate large training gains whereas others feel overwhelmed and hardly improve or even regress ( Jaeggi, Buschkuehl, Jonides, & Shah, 2011). Therefore, considering the role of individual differences seems to be crucial when evaluating the efficacy of training. By doing so, the current study answers numerous calls for more work examining the impact of individual differences on training ( Colquitt et al., 2000, Martocchio and Judge, 1997 and Mount and Barrick, 1998). For example, there is evidence suggesting that the personality traits conscientiousness and neuroticism affect training outcomes ( Colquitt et al., 2000). Furthermore, the finding that individual differences affects how people react to more or less complex tasks (e.g. Walsh, Wilding, & Eysenck, 1994) suggests that the relationship between personality and training outcome might depend on the complexity of the training task. Thus, in the current study, we investigate whether conscientiousness and neuroticism might determine cognitive training performance and transfer to non-trained tasks by using two training tasks that differed in the degree of complexity.
