. Author manuscript; available in PMC: 2012 Jan 1.

Published in final edited form as: Clin Neurophysiol. 2010 Jul 8;122(1):114–120. doi: 10.1016/j.clinph.2010.06.010

Table 1.

Table 1a. Between-day, within-day and total variability of SWMT overall score, and performance, cortical activation and alertness sub-scores, in the absence of a treatment. Data from 127 participants in seven studies (see text)
		Between-day	Within-day	Total Variability

Overall Score	# tests	279	362	641
	M	−0.15	0.00	−0.07
	sd	0.62	0.54	0.58
	CI (95%)	± 0.07	± 0.06	± 0.04
Performance	M	−0.09	0.07	0.00
	sd	0.75	0.63	0.69
	CI (95%)	± 0.09	± 0.07	± 0.05
Activation	M	−0.01	0.19	0.10
	sd	0.86	0.91	0.90
	CI (95%)	± 0.10	± 0.09	± 0.07
Alertness	# tests	245	325	570
	M	−0.28	−0.28	−0.28
	sd	0.89	0.72	0.79
	CI (95%)	± 0.11	± 0.08	± 0.07

Table 1b. Between-day and within-day variability of the overall score in each of the seven studies
	Between-day variability				Within-day variability

	Mean	sd	# tests	CI (95%)	Mean	sd	# tests	CI (95%)
Study1	−0.25	0.74	68	± 0.17	−0.04	0.59	63	± 0.15
Study2	0.03	0.49	29	± 0.18	0.14	0.42	58	± 0.11
Study3	−0.39	0.56	58	± 0.15	−0.06	0.51	86	± 0.11
Study4	0.07	0.55	9	± 0.36	0.06	0.59	72	± 0.14
Study5	−0.02	0.64	47	± 0.18	−0.14	0.58	48	± 0.17
Study6	−0.01	0.46	50	± 0.13	--	--	--	--
Study7	−0.11	0.63	18	± 0.29	−0.06	0.62	30	± 0.22

M = mean; sd = standard deviation; CI = confidence interval. The mean values are all approximately zero with standard deviations less than one.