Table 3.

Caffeine versus nap ‐ all outcome data from neuropsychological tests

	Caffeine			Nap
Subgroup/study	mean	sd	n	mean	sd	n	SMD (95% CIs)
Concept formation and reasoning
Rogers ‐ logic	‐40.1	5.05	6	‐37.28	6.37	6	‐0.45 (‐1.61 to 0.70)
Memory
Rogers ‐ short term memory, av. no. correct	‐10.38	0.83	6	‐9.6	0.96	6	‐0.80 (‐2.00 to 0.40)
Rogers ‐ short term memory, av. no. correct in correct sequence	‐8.74	1.07	6	‐7.4	1.81	6	‐0.83 (‐2.03 to 0.37)
Orientation and attention
Rogers ‐ auditory tracking and vigilance, error score	879.32	898.25	6	1460	1993.27	6	‐0.35 (‐1.49 to 0.80)
Rogers ‐ auditory tracking and vigilance, missed responses %	28.1	42.38	6	44.95	42.3	6	‐0.37 (‐1.51 to 0.78)
Rogers ‐ complex attention, missed responses %	15.28	21.02	6	32.75	19.23	6	‐0.80 (‐2.00 to 0.40)
Rogers ‐ digit symbol substitution, no. substitutions	‐113.94	8.79	6	‐108.6	3.55	6	‐0.74 (‐1.92 to 0.45)
Rogers ‐ sustained attention, missed responses %	4.46	4.55	6	8.45	7.52	6	‐0.59 (‐1.76 to 0.58)
Rogers ‐ visual vigilance, mean RT for correct responses	0.6	0.03	6	0.62	0.02	6	‐0.72 (‐1.91 to 0.46)
Rogers ‐ visual vigilance, missed responses %	24.56	35.98	6	55.98	45	6	‐0.71 (‐1.90 to 0.47)
Schweitzer a ‐ PVT, no. lapses	4.47	2.44	17	4.43	2.44	17	0.02 (‐0.66 to 0.69)
Perception
Rogers ‐ two‐letter cancellation, no. correct	‐79.92	18.89	6	‐70.63	9.39	6	‐0.57 (‐1.74 to 0.59)
Verbal functioning and language skills
Schweitzer a ‐ Torrance test of creative thinking (verbal), flexibility	14.3	17.03	17	18.7	15.87	17	‐0.26 (‐0.94 to 0.41)
Schweitzer a ‐ Torrance test of creative thinking (verbal), fluency	4.68	10.23	17	9.08	11.34	17	‐0.40 (‐1.08 to 0.28)
Schweitzer a ‐ Torrance test of creative thinking (verbal), originality	12.1	20.41	17	10.45	6.8	17	0.11 (‐0.57 to 0.78)