Fig 2. Individual scatter plot showing the relative (%) change scores for mean reaction time (RT) for each participant from baseline (Pre) to after the three consecutive work shifts (Post), and from the end of the first work shift (Mid1) to the end of the third shift (Post).

Note, positive % change indicates poorer RT performance (i.e., an elongated response time versus earlier time trial). Horizontal dashed line represents a 10% reduced performance and is used here as an illustration of a hypothetical threshold where such a performance impairment may begin to negatively impact on-the-job task performance.