> Results: Modafinil improved performance on tests of higher cognitive function; participants in the modafinil group worked more efficiently when solving working memory ... and planning ... problems, were less-impulsive decision makers ... , and were more able to flexibly redirect their attention ... . In contrast, no improvement was seen in tests of clinical psychomotor performance.

> Conclusions: Our results suggest that fatigued doctors might benefit from pharmacological enhancement in situations that require efficient information processing, flexible thinking, and decision making under time pressure. However, no improvement is likely to be seen in the performance of basic procedural tasks.

Sugden et al. (2012) Effect of Pharmacological Enhancement on the Cognitive and Clinical Psychomotor Performance of Sleep-Deprived Doctors. Ann Surg 255:222–227.

https://pdfs.semanticscholar.org/8010/d889309016b93901fd0045...