Cognitive inflexibility in Japanese adolescents and adults with autism spectrum disorders

Table 1 Demographic information for subjects with autism spectrum disorders and controls

	ASD (n = 33)	Control (n = 33)	P value
Sex (male/female)	20/13	20/13	χ2 (1, n = 66) = 1.00 P = 1.00
Age (yr)	26.1 (11.5)	26.8 (9.6)	U = 459.0, Z = –1.10 P = 0.27
Age range (yr)	15-63	18-61
Education years	13.2 (2.9)	14.2 (1.9)	U = 441.0, Z = –1.35 P = 0.18
FIQ	103.0 (16.7)	103.7 (14.7)	U = 534.0, Z = –0.13 P = 0.89
PIQ	96.2 (16.1)	97.8 (15.0)	U = 495.5, Z = –0.63 P = 0.53
VIQ	107.9 (16.3)	107.7 (14.4)	U = 521.0, Z = –0.30 P = 0.76
CPT mean D’ score	3.10 (0.61)	3.38 (0.53)	U = 396.0, Z = –1.90 P = 0.057

Data are represented as the mean ± SD and P value. Differences in clinical characteristics were analyzed using the χ² test for gender and the Mann-Whitney U-test for the other variables. ASD: Autism spectrum disorders; IQ: Intelligence quotient; FIQ: Full-scale IQ; PIQ: Performance IQ; VIQ: Verbal IQ; CPT: Continuous Performance Test.

Table 2 Performance on the Wisconsin Card Sorting Test in subjects with autism spectrum disorders and controls

	ASD (n = 33)	Control (n = 33)	P value
CA	4.76 (1.28)	5.24 (0.90)	U = 433.5, Z = –1.51 P = 0.13
TE	16.03 (6.24)	12.61 (3.52)	U = 350.0, Z = –2.51 P = 0.012a
%PEM	11.69 (10.72)	6.58 (8.87)	U = 389.0, Z = –2.09 P = 0.037a
%PEN	20.09 (14.54)	8.74 (10.41)	U = 294.0, Z = –3.26 P = 0.0011a

Data are represented as the mean ± SD,

^aP < 0.05 vs control; differences in the clinical characteristics were analyzed using the Mann-Whitney U-test. ASD: Autism spectrum disorders; CA: Categories achieved; TE: Total number of errors; %PEM: Percentages of perseverative errors of the Milner type; %PEN: Percentages of perseverative errors of the Nelson type.

Table 3 Correlation between intelligence quotient and performance on the Wisconsin Card Sorting Test in subjects with autism spectrum disorders and controls

	ASD (n = 34)						Control (n = 34)
	FIQ		VIQ		PIQ		FIQ		VIQ		PIQ
	r	P value	r	P value	r	P value	r	P value	r	P value	r	P value
CA	0.24	0.18	0.26	0.20	0.15	0.260	0.22	0.220	0.19	0.29	0.20	0.27
TE	-0.26	0.15	-0.19	0.28	-0.31	0.084	-0.30	0.089	-0.28	0.12	-0.25	0.16
%PEM	-0.26	0.14	-0.23	0.20	-0.26	0.140	-0.31	0.082	-0.32	0.073	-0.22	0.22
%PEN	-0.41	0.019a	-0.42	0.015a	-0.32	0.068	-0.31	0.076	-0.28	0.11	-0.27	0.14

^aP < 0.05 vs control, Pearson’s r was used to correlate performance scores with intelligence quotient for each variable. ASD: Autism spectrum disorders; CA: Categories achieved; TE: Total number of errors; %PEM: Percentages of perseverative errors of the Milner type; %PEN: Percentages of perseverative errors of the Nelson type; IQ: Intelligence quotient; FIQ: Full-scale IQ; PIQ: Performance IQ; VIQ: Verbal IQ.