. Author manuscript; available in PMC: 2008 Apr 1.

Published in final edited form as: Arch Clin Neuropsychol. 2007 Oct 31;23(1):21–32. doi: 10.1016/j.acn.2007.09.002

Table 4.

Mean response time (RT: ms) and standard deviations (sd) in 3 conditions of the switch-task in ADHD cases, their siblings and controls: coefficient of variation in the “Switch” condition

Group:	ADHD		Siblings		Controls
	Mean	(sd)	Mean	(sd)	Mean	(sd)
N:	39		33		38
Condition
“Which number?”	278.4	(149.5)	286.4	(200.6)	268.8	(251.5)
“How many?”	343.7	(187.2)	440.4	(403.0)	360.8	(270.9)
“Switch”	703.9¹	(147.6)	662.2	(156.7)	642.9	(140.1)

Coefficient of variation
“Switch”	.51²,³	(.06)	.48	(.06)	.46	(.06)

Coefficient of variation = SD of mean RT/RT:

ADHD vs. controls, t = 1.9, p = .067:

ADHD vs. Siblings, t = 2.25, p = .028:

ADHD vs. controls, t = 3.28, p = .002