Table 4.
Performance on Attention Tasks
| Task | Group | –1 Week (baseline) | 0 Week (single dose) | 12 Weeks | |
|---|---|---|---|---|---|
| ST (Part 1) | Simple reaction time (A) | Placebo | 411 ± 145 | 365 ± 62.0 | 337 ± 43.8 |
| Theanine | 378 ± 138 | 337 ± 84.0* | 328 ± 59.6 | ||
| (Part 2) | Complex reaction time correct (B) | Placebo | 734 ± 124 | 706 ± 133 | 679 ± 80.1 |
| Theanine | 706 ± 122 | 667 ± 97.8 | 650 ± 70.1 | ||
| (Part 3) | Stroop reaction time correct (C) | Placebo | 841 ± 129 | 809 ± 98.2 | 788 ± 91.1 |
| Theanine | 802 ± 121 | 761 ± 120 | 754 ± 106 | ||
| Stroop commission errors | Placebo | 1.23 ± 1.6 | 0.96 ± 1.0 | 0.83 ± 1.1 | |
| Theanine | 0.73 ± 0.96 | 0.69 ± 1.0 | 0.77 ± 0.76 | ||
| (C/B) × 100 | Placebo | 115 ± 13 | 116 ± 14 | 117 ± 13 | |
| Theanine | 115 ± 14 | 115 ± 12 | 116 ± 10 | ||
| (A/B) × 100 | Placebo | 55.4 ± 14 | 52.2 ± 7.2 | 50.2 ± 7.9 | |
| Theanine | 52.9 ± 11 | 50.3 ± 7.4 | 50.4 ± 7.0 | ||
| SAT | Correct responses | Placebo | 41.0 ± 8.3 | 46.3 ± 6.8 | 46.8 ± 7.4 |
| Theanine | 45.0 ± 8.0 | 48.6 ± 5.0 | 50.2 ± 5.4 | ||
| Errors | Placebo | 5.7 ± 5.0 | 3.9 ± 4.0 | 3.8 ± 4.0 | |
| Theanine | 4.7 ± 3.6 | 4.0 ± 2.4 | 3.3 ± 2.0 | ||
| Correct reaction time | Placebo | 1266 ± 144 | 1151 ± 121 | 1144 ± 163 | |
| Theanine | 1167 ± 157 | 1067 ± 132 | 1045 ± 134 | ||
| CPT | Correct responses | Placebo | 38.8 ± 2.3 | 39.5 ± 0.8 | 39.7 ± 0.6 |
| Theanine | 39.6 ± 1.4 | 39.8 ± 0.5 | 39.7 ± 1.0 | ||
| Omission errors | Placebo | 1.15 ± 2.3 | 0.46 ± 0.81 | 0.29 ± 0.62 | |
| Theanine | 0.38 ± 1.4 | 0.15 ± 0.46 | 0.31 ± 0.97 | ||
| Commission errors | Placebo | 0.54 ± 0.95 | 0.38 ± 0.75 | 0.29 ± 0.55 | |
| Theanine | 0.15 ± 0.46 | 0.15 ± 0.37 | 0.27 ± 0.45 | ||
| Choice reaction time correct | Placebo | 511 ± 50.7 | 500 ± 43.8 | 493 ± 42.1 | |
| Theanine | 492 ± 80.4 | 483 ± 72.1 | 474 ± 47.7 | ||
| FPCPT (Part 1) | Average correct response time | Placebo | 403 ± 91 | 394 ± 100 | 359 ± 48 |
| Theanine | 409 ± 132 | 359 ± 62 | 347 ± 53 | ||
| (Part 2) | Correct responses | Placebo | 5.7 ± 1.1 | 5.9 ± 0.3 | 5.7 ± 1.2 |
| Theanine | 5.8 ± 0.8 | 6.0 ± 0.2 | 5.8 ± 1.2 | ||
| Average correct response time | Placebo | 486 ± 62 | 461 ± 50 | 440 ± 105 | |
| Theanine | 476 ± 95 | 440 ± 75 | 420 ± 96 | ||
| Incorrect responses | Placebo | 0.38 ± 0.75 | 0.15 ± 0.37 | 0.42 ± 1.1 | |
| Theanine | 0.23 ± 0.86 | 0.15 ± 0.61 | 0.04 ± 0.20 | ||
| Average incorrect response time | Placebo | 144 ± 253 | 68.3 ± 171 | 74.3 ± 175 | |
| Theanine | 36.7 ± 134 | 31.6 ± 117 | 16.7 ± 85 | ||
| Omission errors | Placebo | 0.31 ± 1.1 | 0.08 ± 0.27 | 0.29 ± 1.2 | |
| Theanine | 0.19 ± 0.80 | 0.04 ± 0.20 | 0.23 ± 1.2 |
Values are presented as mean ± SD.
*
P < .05/3 = 0.017 versus placebo group. P values were calculated using the unpaired t-test or Mann–Whitney U test and Bonferroni correction.
CPT, continuous performance test; FPCPT, four-part continuous performance test; SAT, shifting attention test; ST, stroop test.