Table 2.

Behavioural performance during the auditory oddball task in caffeine, placebo and baseline conditions (mean ± standard deviation across subjects).

Conditions	Reaction time (ms)	Number of misses	Number of false alarms
Baseline placebo (BP)	603 ± 138	4.7 ± 4.1	1.8 ± 1.5
Baseline caffeine (BC)	609 ± 126	4.9 ± 3.8	1.7 ± 1.6
(BC-BP)	6 ± 59	0.1 ± 1.6	− 0.1 ± 2.0
Placebo (DP)	599 ± 130	5.4 ± 5.2	2.1 ± 1.4
Caffeine (DC)	598 ± 145	2.7 ± 1.9+⁎§	1.5 ± 1.2
(DC–DP)	1 ± 81	− 2.7 ± 3.0	− 0.6 ± 1.5

⁺Significant interaction effect of dosing (baseline or post-dose scan) × drug (placebo or caffeine) in a 2-way repeated-measures ANOVA, p < 0.05.

^⁎Significantly different with respect to baseline caffeine (two-tailed post-hoc paired t-test p < 0.05).

^§Significantly different with respect to placebo (two-tailed post-hoc paired t-test p < 0.05).