Table 1.

Participant characteristics. Table 1.A displays characteristics of participants involved in the comparison analysis (section 1). This section included 35 children with ADHD combined type (ADHD-C) and 64 control children. Table 1.B displays characteristics of participants involved in the correlation analysis (section 2), which included 52 children with ADHD and 70 children without ADHD.

A. Comparison Analysis - Section 1
Variable	Controls		ADHD-C		p
	Mean	SD	Mean	SD
Age	9.21	1.20	9.57	1.47	0.19
IQ	116.91	12.82	109.24	14.93	0.01 *
Movement (RMS)	0.41	0.32	0.43	0.34	0.81
Frame-to-frame displacement (FD)	0.28	0.22	0.30	0.25	0.63
ln(k)	−3.87	1.94	−2.87	2.59	0.07 **
	N	%	N	%
Gender
Male	39	60.94	27	77.14
Female	25	39.06	8	22.86

B. Correlation Analysis - Section 2
Variable	Controls		ADHD		p
	Mean	SD	Mean	SD
Age	9.00	1.21	9.63	1.35	0.01 *
IQ	117	13.08	110.80	15.51	0.02 *
Movement (RMS)	0.40	0.33	0.47	0.32	0.27
Frame-to-frame displacement (FD)	0.27	0.23	0.32	0.21	0.22
ln(k)	−3.77	2.06	−2.97	2.83	0.09 ***
	N	%	N	%
Gender
Male	34	48.57	38	73.08
Female	36	51.43	14	26.92
ADHD subtype
Combined	-	-	30	57.69
Inattentive	-	-	21	40.38
Hyperactive	-	-	1	1.92

SD, standard deviation; IQ, Full-Scale IQ; ln(k), natural log of the discounting gradient (k).

^*indicates p value < 0.05;

^**p value = 0.027, when adjusting for age;

^***p value = 0.015, when adjusting for age.