Table 5.
Task | −4 Weeks (1) | 0 Weeks (2) | 12 weeks (3) | Change from Baseline | p-Values (KW Test) | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
(Baseline) | (Single Dose) | 0 W (4) | 12 W (5) | (1) | (2) | (3) | (4) | (5) | ||||
ST (part 1) | Simple reaction time | Placebo | 341 ± 40 | 336 ± 48 | 333 ± 51 | −5.29 ± 40 | −8.00 ± 46 | 0.50 | 0.78 | 0.42 | 0.14 | 0.67 |
(ms) [A] | Caffeine | 343 ± 72 | 333 ± 55 | 341 ± 42 | −10.0 ± 59 | −2.18 ± 67 | ||||||
Matcha | 410 ± 228 | 327 ± 35 | 356 ± 54 | −82.8 ± 203 | −52.5 ± 206 | |||||||
(part 2) | Complex reaction time, | Placebo | 719 ± 81 | 687 ± 72 | 674 ± 82 | −32.4 ± 57 | −44.8 ± 66 | 0.15 | 0.29 | 0.58 | 0.52 | 0.11 |
correct (ms) [B] | Caffeine | 661 ± 91 | 648 ± 78 | 676 ± 103 | −13.0 ± 76 | 15.6 ± 113 | ||||||
Matcha | 716 ± 180 | 655 ± 58 | 638 ± 44 | −60.9 ± 161 | −77.6 ± 174 | |||||||
(part 3) | Stroop reaction time, | Placebo | 811 ± 88 | 766 ± 94 | 755 ± 78 | −45.2 ± 92 | −55.9 ± 8.0 | 0.38 | 0.65 | 0.93 | 0.98 | 0.21 |
correct (ms) [C] | Caffeine | 770 ± 96 | 732 ± 80 | 759 ± 104 | −38.2 ± 54 | −11.6 ± 77 | ||||||
Matcha | 825 ± 169 | 761 ± 101 | 751 ± 85 | −63.6 ± 122 | −74.3 ± 130 | |||||||
Stroop commission | Placebo | 0.47 ± 0.5 | 0.65 ± 0.9 | 0.59 ± 0.6 | 0.18 ± 0.9 | 0.12 ± 0.7 | 0.09 | 0.25 | 0.89 | 0.01 | 0.50 | |
Errors | Caffeine | 0.53 ± 0.8 | 1.00 ± 1.0 | 0.82 ± 1.2 | 0.47 ± 1.1 | 0.29 ± 1.6 | ||||||
Matcha | 0.94 ± 0.7 | 0.47 ± 0.6 | 0.77 ± 0.8 | −0.47 ± 0.9 † | −0.18 ± 1.1 | |||||||
(C/B) × 100 | Placebo | 114 ± 14 | 112 ± 11 | 113 ± 8.8 | −1.84 ± 15 | −1.16 ± 15 | 0.68 | 0.51 | 0.26 | 0.66 | 0.44 | |
Caffeine | 118 ± 15 | 114 ± 11 | 113 ± 10 | −3.93 ± 13 | −4.82 ± 18 | |||||||
Matcha | 116 ± 10 | 116 ± 9.1 | 118 ± 12 | −0.21 ± 14 | 1.46 ± 14 | |||||||
(A/B) × 100 | Placebo | 47.7 ± 5.9 | 48.9 ± 5.2 | 49.5 ± 5.7 | 1.23 ± 6.7 | 1.79 ± 7.3 | 0.24 | 0.66 | 0.20 | 0.19 | 0.69 | |
Caffeine | 51.9 ± 7.9 | 51.7 ± 8.2 | 51.1 ± 7.3 | −0.24 ± 7.8 | −0.89 ± 9.0 | |||||||
Matcha | 55.9 ± 16 | 50.4 ± 7.2 | 56.2 ± 10 | −5.57 ± 12 | 0.28 ± 11 | |||||||
SAT | Correct responses | Placebo | 44.9 ± 7.5 | 47.0 ± 8.2 | 47.3 ± 7.1 | 2.12 ± 3.7 | 2.41 ± 3.8 | 0.45 | 0.09 | 0.11 | 0.06 | 0.89 |
Caffeine | 47.2 ± 6.4 | 52.6 ± 5.0 | 51.3 ± 4.3 | 5.41 ± 5.8 | 4.12 ± 6.6 | |||||||
Matcha | 42.7 ± 13 | 50.0 ± 7.2 | 47.6 ± 7.7 | 7.29 ± 10 | 4.94 ± 11 | |||||||
Errors | Placebo | 4.77 ± 3.3 | 3.88 ± 3.5 | 3.65 ± 3.1 | −0.88 ± 2.3 | −1.12 ± 2.3 | 0.22 | 0.13 | 0.18 | 0.82 | 0.84 | |
Caffeine | 3.59 ± 3.5 | 1.88 ± 2.4 | 2.00 ± 1.5 | −1.71 ± 3.2 | −1.59 ± 3.9 | |||||||
Matcha | 7.24 ± 7.8 | 3.41 ± 3.4 | 3.59 ± 3.1 | −3.82 ± 7.7 | −3.65 ± 7.1 | |||||||
Reaction time, | Placebo | 1175 ±153 | 1152 ± 187 | 1147 ± 176 | −23.4 ± 106 | −27.9 ± 108 | 0.88 | 0.06 | 0.19 | 0.049 | 0.12 | |
correct (ms) | Caffeine | 1148 ± 129 | 1033 ± 107 # | 1053 ± 121 | −115 ± 96 * | −94.8 ± 102 | ||||||
Matcha | 1154 ± 197 | 1054 ± 145 | 1114 ± 148 | −101 ± 152 | −40.2 ± 190 | |||||||
CPT | Correct responses | Placebo | 39.8 ± 0.4 | 39.4 ± 1.6 | 39.4 ± 1.5 | −0.47 ± 1.6 | −0.41 ± 1.6 | 0.17 | 0.53 | 0.39 | 0.99 | 0.92 |
Caffeine | 39.9 ± 0.5 | 39.5 ± 1.7 | 39.8 ± 0.7 | −0.35 ± 1.8 | −0.06± 0.9 | |||||||
Matcha | 40.0 ± 0.0 | 39.9 ± 0.2 | 39.9 ± 0.2 | −0.06 ± 0.2 | −0.06 ± 0.2 | |||||||
Omission errors | Placebo | 0.18 ± 0.4 | 0.65 ± 1.6 | 0.59 ± 1.5 | 0.47 ± 1.6 | 0.41 ± 1.6 | 0.17 | 0.53 | 0.39 | 0.99 | 0.92 | |
Caffeine | 0.12 ± 0.5 | 0.47 ± 1.7 | 0.18 ± 0.7 | 0.35 ± 1.8 | 0.06 ± 0.9 | |||||||
Matcha | 0.00 ± 0.0 | 0.06 ± 0.2 | 0.06 ± 0.2 | 0.06 ± 0.2 | 0.06 ± 0.2 | |||||||
Commission errors | Placebo | 0.24 ± 0.4 | 0.06 ± 0.2 | 0.24 ± 0.4 | −0.18 ± 0.4 | 0.00 ± 0.6 | 0.95 | 0.57 | 0.61 | 0.73 | 0.77 | |
Caffeine | 0.29 ± 0.7 | 0.12 ± 0.3 | 0.24 ± 0.4 | −0.18 ± 0.7 | −0.06 ± 0.7 | |||||||
Matcha | 0.29 ± 0.6 | 0.18 ± 0.4 | 0.12 ± 0.3 | −0.12 ± 0.6 | −0.18 ± 0.6 | |||||||
Reaction time, | Placebo | 480 ± 46 | 496 ± 53 | 482 ± 46 | 15.6 ± 41 | 2.00 ± 25 | 0.90 | 0.26 | 0.99 | <0.01 | 0.47 | |
correct (ms) | Caffeine | 484 ± 44 | 468 ± 38 | 480 ± 40 | −16.1 ± 19 * | −4.35 ± 38 | ||||||
Matcha | 515 ± 108 | 470 ± 38 | 480 ± 33 | −45.5 ± 98 ** | −35.8 ± 94 | |||||||
FPCPT | Average response time, | Placebo | 386 ± 64 | 385 ± 72 | 348 ± 42 | −1.29 ± 53 | −37.5 ± 46 | 0.36 | 0.11 | 0.56 | 0.51 | 0.99 |
(part 1) | correct (ms) | Caffeine | 395 ± 82 | 364 ± 33 | 355 ± 41 | −31.1 ± 60 | −39.5 ± 61 | |||||
Matcha | 448 ± 137 | 403 ± 55 | 369 ± 55 | −44.2 ± 117 | −78.3 ± 137 | |||||||
(part 2) | Correct responses | Placebo | 6.00 ± 0.0 | 5.94 ± 0.2 | 5.59 ± 1.5 | −0.06 ± 0.2 | −0.41 ± 1.5 | 0.13 | 0.37 | 0.13 | 0.10 | 0.05 |
Caffeine | 5.82 ± 0.5 | 6.00 ± 0.0 | 6.00 ± 0.0 | 0.18 ± 0.5 | 0.18 ± 0.5 | |||||||
Matcha | 6.00 ± 0.0 | 6.00 ± 0.0 | 6.00 ± 0.0 | 0.00 ± 0.0 | 0.00 ± 0.0 | |||||||
Average response time, | Placebo | 447 ± 56 | 450 ± 65 | 428 ± 124 | 2.94 ± 42 | −18.9 ± 119 | 0.48 | 0.51 | 0.85 | 0.03 | 0.31 | |
correct (ms) | Caffeine | 464 ± 56 | 432 ± 40 | 441 ± 51 | −31.8 ± 41 * | −22.7 ± 53 | ||||||
Matcha | 473 ± 76 | 433 ± 43 | 444 ± 52 | −40.4 ± 66 | −29.7 ± 67 | |||||||
Incorrect responses | Placebo | 0.24 ± 0.4 | 0.00 ± 0.0 | 0.24 ± 0.4 | −0.24 ± 0.4 | 0.00 ± 0.7 | 0.06 | 0.06 | 0.43 | 0.048 | 0.12 | |
Caffeine | 0.35 ± 0.6 | 0.29 ± 0.5 | 1.00 ± 4.1 | −0.06 ± 0.6 | 0.65 ± 4.3 | |||||||
Matcha | 0.00 ± 0.0 | 0.18 ± 0.4 | 1.06 ± 3.9 | 0.18 ± 0.4 * | 1.06 ± 3.9 | |||||||
Average response time, | Placebo | 118 ± 221 | 0.00 ± 0.0 | 92.9 ± 175 | −118 ± 221 | −25.4 ± 321 | 0.07 | 0.07 | 0.38 | 0.04 | 0.15 | |
incorrect (ms) | Caffeine | 158 ± 265 | 122 ± 206 | 26.6 ± 110 | −35.5 ± 229 | −131 ± 302 | ||||||
Matcha | 0.00 ± 0.0 | 72.1 ± 161 | 59.1 ± 135 | 72.1 ± 161 * | 59.1 ± 135 | |||||||
Omission errors | Placebo | 0.00 ± 0.0 | 0.06 ± 0.2 | 0.41 ± 1.5 | 0.06 ± 0.2 | 0.41 ± 1.5 | 0.13 | 0.37 | 0.13 | 0.10 | 0.05 | |
Caffeine | 0.18 ± 0.5 | 0.00 ± 0.0 | 0.00 ± 0.0 | −0.18 ± 0.5 | −0.18 ± 0.5 | |||||||
Matcha | 0.00 ± 0.0 | 0.00 ± 0.0 | 0.00 ± 0.0 | 0.00 ± 0.0 | 0.00 ± 0.0 |
Values are presented as the mean ± standard deviation. Group (inter) analysis was performed using the Kruskal–Wallis test (KW) followed by a post-hoc Mann–Whitney U test at each time point to test for inter-group outcomes (control vs. caffeine, control vs. matcha, and caffeine vs. matcha). The p-value was determined using a Bonferroni correction of * p < 0.05/3 = 0.017; ** p < 0.01/3 = 0.0033 vs. placebo group; † p < 0.05/3 = 0.017, caffeine group vs. matcha group. (1) (2) (3) (4) (5) The numbers in brackets at −4 weeks, 0 weeks and 12 weeks corresponded to the numbers listed in the column with the p-value for the KW test. Time (intra) was analyzed using Dunnett’s test (T3) for intra-group comparisons, using the baseline condition as the reference (baseline vs. 0 W and baseline vs. 12 W). The p-value was determined using a Bonferroni correction of # p < 0.05/2 = 0.025. Abbreviations: ST, Stroop test; SAT, Shifting Attention test; CPT, Continuous Performance test; FPCPT, 4-part Continuous Performance test; KW, Kruskal–Wallis test; W, weeks.