Figure 1.

Time course of effects for driving-related skills (differences to baseline). Data points and error bars represent mean and SD values for 16 participants. Conditions: alcohol (60 g); alcohol (60 g) + RB (240 mg caffeine); RB (240 mg caffeine); placebo. * P < .05 and ** P < .01 indicate alcohol significant differences with A/RB. Filled symbols indicate a significant difference from placebo (P < .05). The significance is only reported for the comparison of more interest (A vs A/RB) and also between all conditions and placebo. Other comparisons are not included in the figure to make it easy to understand.