. 2020 Mar 12;74(5):757–764. doi: 10.1038/s41430-020-0600-0

Table 2.

Effects of lunch with medium and high GI rice on cognitive performance in schoolchildren.

	Medium-high GI						High-medium GI
	Period 1			Period 2			Period 1			Period 2			GI
	$\tilde{x}$	25th	75th	$\tilde{x}$	25th	75th	$\tilde{x}$	25th	75th	$\tilde{x}$	25th	75th	p
Switch (n = 170)
Switch costs [s]	26.6	16.3	35.2	19.7	10.5	31.2	25.2	14.9	36.7	20.0	11.4	28.2	0.68*
Visual search letters [s]^‡	30.0	26.2	35.8	30.0	25.3	36.6	29.2	25.4	37.0	29.5	25.5	36.7	0.14
Visual search numbers [s]	45.7	40.2	52.9	48.4	41.8	56.9	45.9	40.3	51.8	49.7	43.1	56.8	0.54*
2-back (n = 188)
RT [ms]	559.5	497.7	641.8	535.2	459.1	608.0	533.6	426.1	604.4	488.5	421.1	572.4	0.001^a
Ratio of missings (%)	33.3	19.0	42.9	33.3	19.0	47.6	28.6	19.0	42.9	33.3	19.0	47.6	0.92*
Ratio of false alarms (%)	7.1	3.5	15.3	5.9	2.4	11.8	7.1	2.4	17.6	5.9	1.2	13.5	0.41^#,*
Alertness (n = 188)
Mean RT [ms]	332.5	303.5	369.9	356.6	314.2	400.8	330.9	296.6	382.3	357.1	310.2	391.9	0.42*
Deviation of RT [ms]	112.2	80.8	155.9	135.0	98.6	179.5	100.6	76.1	151.1	125.0	90.2	176.6	0.94^#,*
Count of omission errors (n)	0	0	1	0	0	1	0	0	1	0	0	1	0.24^#
Count of commission errors (n)	2	1	4	2	1	4	1	1	3	1	0	3	0.04^#,a

Medium-high GI: participants received lunch with medium GI rice in the first period and high GI rice in the second period; high-medium GI: vice versa.

GI glycemic index, GL glycemic load, RT reaction time.

^‡First 12 reactions; switch costs = (mean RT switch task) − (mean RT number task) − (mean RT first 12 reactions of letter task − mean RT first 12 reactions of number task). $\tilde{x}$ = Median (presented in bold), 25th and 75th percentiles; two sample t test.

^#Wilcoxon’s ranked sum test.

*Period effects detected using linear mixed model.

^ap values for RT (two back) and count of commission errors (alertness) were only calculated for period 1.