Autistic traits and neuropsychological performance in 6- to-10-year-old children: a population-based study

Figures & data

Figure 1. Flow diagram depicting the study sample inclusion.

Table 1. Demographic and clinical characteristics of the study sample.

	Study sample (n = 1019)
Demographics	Observations	Number	Percentage (%)
Gender	1019
Male		541	53.1
Female		478	46.9
Ethnicity	1019
Dutch		739	72.5
Other Western		77	7.6
Non-Western		203	19.9
Maternal characteristics
Education level	991
High		499	50.4
Medium		436	44.0
Low		56	5.7
Monthly income	898
High		639	71.2
Medium		167	18.6
Low		92	10.2
Maternal smoking habits	952
Never smoked during pregnancy		725	76.2
Smoked until pregnancy was known		67	7.0
Continued smoking in pregnancy		160	16.8
Maternal alcohol consumption	950
Never drank in pregnancy		339	35.6
Drank until pregnancy was known		139	14.6
Continued drinking occasionally		372	39.2
Continued drinking frequently		100	10.5
Clinical and cognitive measures	Observations	Mean (SD)	Min	Max
SRS	1019	0.29 (0.32)	0	2.66
CBCL total attention problem score	994	2.07 (2.13)	0	10
Nonverbal-IQ	920	102.18 (14.6)	50	142

Table 2. Neuropsychological performance between children with an autism spectrum disorder diagnosis and typically developing children.

	Autism spectrum disorder		Typical development
	Mean	SD	Mean	SD
Attention and executive functioning Auditory attention
Total score	27.29	3.85	27.76	3.04
Commission errors	6.41	23.56	1.64	5.66
Omission errors	2.70	3.85	2.23	3.04
Inhibition errors	1.32	5.62	0.74	3.81
Response set
Total score	26.97	8.43	29.26	5.37
Commission errors	7.15	10.34	3.73	3.63
Omission errors	9.02	8.43	6.73	5.38
Inhibition errors	2.56	5.62	1.47	2.19
Statue
Total score	26.62	5.29	28.01	3.26
Total movements	1.65	2.72	0.97	1.98
Total sounds	0.96	2.38	0.57	1.33
Total eye openings	1.21	1.42	0.73	1.36
Language
Word generation
Total semantic score	23.39	10.92	26.77	7.91
Memory and learning
Memory for faces – Total Score	9.28	2.70	10.72	2.23
Memory for faces – delayed – Total Score	9.58	3.10	10.98	2.52
Narrative memory
Total score free and cued recall	16.53	7.21	19.69	5.86
Total score free recall	11.2	7.75	15.40	6.97
Total score recognition	13.81	1.58	14.16	1.43
Sensorimotor function
Visuomotor Precision
Total time	115.62	55.23	107.65	44.74
Total errors	26.33	28.94	19.54	23.87
Total pencil lifts	5.42	8.57	4.69	6.66
Geometric puzzles – total score	25.74	4.65	27.22	4.35
Route finding – total score	6.97	3.46	7.15	2.79

Table 3. Model adjustments controlling for gender and age (Model I) and five additional covariates (Model II).

ASD/Control (n = 1019)
	Model I					Model II
	ASD/TD n	p	B	CI 2.5%	CI 97.5%	p	B	CI 2.5%	CI 97.5%
Attention and executive functioning	41/978	.001	−0.48	−0.77	−0.19	.02	−0.41	−0.76	−0.07
Memory and learning	41/978	.000	−0.64	−0.9	−0.39	.000	−0.63	−0.95	−0.31
Sensorimotor functioning	41/978	.019	−0.32	−0.59	−0.05	.003	−0.49	−0.82	−0.16
Language	41/978	.015	−0.34	−0.61	−0.06	.006	−0.46	−0.79	−0.13
Visuospatial functioning	41/978	.01	−0.37	−0.65	−0.08	.347	−0.16	−0.48	0.17
SRS along a continuum (n = 1019)
Attention and executive functioning		.000	−0.57	−0.78	−0.36	.0005	−0.43	−0.67	−0.19
Memory and learning		.000	−0.73	−0.92	−0.55	.000	−0.6	−0.82	−0.38
Sensorimotor functioning		.000	−0.4	−0.59	−0.20	.002	−0.36	−0.59	−0.14
Language		.000	−0.6	−0.79	−2.90	.003	−0.35	−0.58	−0.12
Visuospatial functioning		.000	−0.68	−0.88	−0.47	.007	−0.31	−0.54	−0.08
NEPSY-II after excluding high SRS and ASD (n = 960)
Attention and executive functioning		.0006	−0.42	−0.66	−0.18	.056	−0.26	−0.53	0.01
Memory and learning		.000	−0.67	−0.89	−0.44	.000	−0.54	−0.79	−0.28
Sensorimotor functioning		.04	−0.24	−0.47	−0.01	.383	−0.11	−0.37	0.14
Language		.000	−0.68	−0.92	−0.44	.004	−0.4	−0.66	−0.13
Visuospatial functioning		.000	−0.7	−0.94	−0.45	.025	−0.31	−0.57	−0.04

Model I – adjusted for age and gender.

Model II – adjusted for age, gender, child ethnicity, maternal education, household income, maternal alcohol use, and smoking during pregnancy.

Figure 2. NEPSY-II performance across five different neuropsychological domains evaluating (top) an ASD/control analysis, (middle) SRS along the continuum with neuropsychological performance, and (bottom) SRS along the continuum with neuropsychological performance after excluding children with ASD and clinical SRS scores. Model I is adjusted only for age and gender, and Model II is additionally adjusted for age at SRS, gender, child ethnicity, maternal education, household income, maternal alcohol use, and smoking during pregnancy.