Table 7.

Effect of matcha or caffeine intake on working memory-related tasks.

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)
FPCPT	Correct responses	Placebo	15.1 ± 1.8	15.5 ± 0.9	15.3 ± 1.0	0.35 ± 2.1	0.18 ± 1.8	0.99	0.88	0.41	0.90	0.87
(part 3)		Caffeine	15.1 ± 1.7	15.5 ± 1.0	15.6 ± 0.7	0.41 ± 1.6	0.53 ± 1.9
		Matcha	15.4 ± 0.9	15.6 ± 0.6	15.5 ± 0.8	0.24 ± 0.8	0.12 ± 1.3
	Average response time,	Placebo	590 ± 102	572 ± 126	614 ± 131	−18.2 ± 7.9	24.2 ± 72	0.31	0.51	0.06	0.80	0.41
	correct (ms)	Caffeine	543 ± 101	528 ± 93	529 ± 107	−15.2 ± 68	−13.5 ± 126
		Matcha	565 ± 115	557 ± 111	544 ± 77	−8.24 ± 57	−20.9 ± 108
	Incorrect responses	Placebo	0.00 ± 0.0	0.06 ± 0.2	0.06 ± 0.2	0.06 ± 0.2	0.06 ± 0.2	0.37	0.59	0.42	0.58	0.81
		Caffeine	0.00 ± 0.0	0.18 ± 0.4	0.06 ± 0.2	0.18 ± 0.4	0.06 ± 0.2
		Matcha	0.06 ± 0.2	0.18 ± 0.5	0.18 ± 0.4	0.12 ± 0.6	0.12 ± 0.5
	Average response time,	Placebo	0.00 ± 0.0	42.1 ± 173	57.1 ± 235	42.1 ± 173	57.1 ± 235	0.37	0.56	0.44	0.52	0.83
	incorrect (ms)	Caffeine	0.00 ± 0.0	139 ± 348	61.5 ± 254	139 ± 348	61.5 ± 254
		Matcha	71.2 ± 293	65.9 ± 189	216 ± 633	−5.24 ± 363	144 ± 720
	Omission errors	Placebo	0.88 ± 1.8	0.53 ± 0.9	0.71 ± 1.0	−0.35 ± 2.1	−0.18 ± 1.8	0.99	0.88	0.41	0.90	0.87
		Caffeine	0.88 ± 1.7	0.47 ± 1.0	0.35 ± 0.7	−0.41 ± 1.6	−0.53 ± 1.9
		Matcha	0.59 ± 0.9	0.35 ± 0.6	0.47 ± 0.8	−0.24 ± 0.8	−0.12 ± 1.3
(part 4)	Correct responses	Placebo	10.7 ± 2.4	11.5 ± 3.0	12.3 ± 2.8	0.82 ± 3.0	1.59 ± 2.2	0.03	0.40	0.56	0.27	0.05
		Caffeine	12.6 ± 2.3	12.8 ± 2.1	13.1 ± 2.0	0.18 ± 2.6	0.53 ± 2.3
		Matcha	12.7 ± 2.6	12.2 ± 2.0	12.4 ± 2.2	−0.47 ± 2.6	−0.35 ± 2.5
	Average response time,	Placebo	745 ± 124	748 ± 143	712 ± 173	2.94 ± 132	−33.2 ± 149	0.21	0.04	0.16	0.50	0.60
	correct (ms)	Caffeine	667 ± 146	618 ± 145 *	625 ± 123	−48.6 ± 120	−41.4 ± 117
		Matcha	722 ± 119	692 ± 140	646 ± 104	−29.8 ± 123	−76.5 ± 124
	Incorrect responses	Placebo	1.65 ± 2.0	1.12 ± 0.9	1.12 ± 1.9	−0.53 ± 1.6	−0.53 ± 2.3	0.54	0.51	0.19	0.34	0.30
		Caffeine	1.41 ± 1.2	1.82 ± 1.7	1.47 ± 1.1	0.41 ± 1.7	0.06± 1.0
		Matcha	1.00 ± 1.2	1.47 ± 1.5	1.65 ± 1.5	0.47± 1.5	0.65± 1.5
	Average response time,	Placebo	439 ± 443	795 ± 546	511 ± 553	356 ± 642	71.8 ± 747	0.15	0.22	0.57	0.02	0.38
	incorrect (ms)	Caffeine	760 ± 568	515 ± 392	623 ± 484	−245 ± 555 *	−137 ± 725
		Matcha	534 ± 583	615 ± 483	687 ± 457	81.1 ± 568	153 ± 779
	Omission errors	Placebo	5.29 ± 2.4	4.47 ± 3.0	3.71 ± 2.8	−0.82 ± 3.0	−1.59 ± 2.2	0.03	0.40	0.56	0.27	0.05
		Caffeine	3.41 ± 2.3	3.24 ± 2.1	2.88 ± 2.0	−0.18± 2.6	−0.53 ± 2.3
		Matcha	3.29 ± 2.6	3.77 ± 2.0	3.65 ± 2.2	0.47± 2.6	0.35± 2.5

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. (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). Abbreviations: FPCPT, 4-part Continuous Performance test; KW, Kruskal–Wallis test; W, weeks.