A custom magnetoencephalography device reveals brain connectivity and high reading/decoding ability in children with autism

Abstract

A subset of individuals with autism spectrum disorder (ASD) performs more proficiently on certain visual tasks than may be predicted by their general cognitive performances. However, in younger children with ASD (aged 5 to 7), preserved ability in these tasks and the neurophysiological correlates of their ability are not well documented. In the present study, we used a custom child-sized magnetoencephalography system and demonstrated that preserved ability in the visual reasoning task was associated with rightward lateralisation of the neurophysiological connectivity between the parietal and temporal regions in children with ASD. In addition, we demonstrated that higher reading/decoding ability was also associated with the same lateralisation in children with ASD. These neurophysiological correlates of visual tasks are considerably different from those that are observed in typically developing children. These findings indicate that children with ASD have inherently different neural pathways that contribute to their relatively preserved ability in visual tasks.

Figure 1

(a) A custom, child-sized MEG. (b) A conventional, adult-sized MEG. (c) The schema of the five selected sensors and the 10 intrahemispheric connections of interest in each hemisphere. F = selected sensor in frontal region; C = central; P = parietal; O = occipital; and T = temporal.

Figure 2

(a) The performance of young children with ASD and TD children on the verbal reasoning test, the pattern reasoning test and the reading/decoding test. The error bars represent 1 standard deviation. (b) A scatter plot is depicted of the two scores (i.e., for the verbal reasoning test and the pattern reasoning test) for the children with ASD and the TD children. (c) A scatter plot is depicted of two scores (i.e., the verbal reasoning test and the reading/decoding test) for the children with ASD and the TD children. Certain children with ASD with low verbal-reasoning test scores achieved relatively high scores on pattern reasoning or reading/decoding tests.

Figure 3. The standardised regression coefficients (β values) are shown for the pattern reasoning performance (one of the two independent variables) in the multiple regression model that was used to predict (a) left, (b) right intrahemispheric coherence and the corresponding laterality index (c) (i.e., the dependent variables), using age as the other independent variable, in the children with ASD.

In sub-figures (a) and (b), the upward direction (positive β value) signifies a positive correlation between the pattern reasoning ability and the coherence value. In sub-figure (c), the upward direction (negative β value) signifies a positive correlation between the pattern reasoning ability and the rightward brain laterality. The β values are presented for P < 0.05. F = selected sensor in the frontal region; C = central; P = parietal; O = occipital; and T = temporal. *P < 0.00056.

Figure 4. The standardised regression coefficients (β values) are shown for reading ability (one of two independent variables) in the multiple regression model that was used to predict (a) left, (b) right intrahemispheric coherence and the corresponding laterality index (c) (i.e., the dependent variables), with age as the other independent variable, in children with ASD.

In sub-figures (a) and (b), the upward direction (positive β value) signifies a positive correlation between the reading ability and the coherence value. In sub-figure (c), the upward direction (negative β value) signifies a positive correlation between the reading ability and the rightward brain laterality. The β values are presented for P < 0.05. F = the selected sensor in frontal region; C = central; P = parietal; O = occipital; and T = temporal. *P < 0.00056.

Figure 5. The standardised regression coefficients (β values) are topographically indicated.

These values were calculated for reading ability (i.e., one of the two independent variables) to predict gamma-2 band coherence between the seed sensor and the remaining 150 sensors (i.e., dependent variables) in children with ASD. (a) A seed sensor was selected in the right parietal region. Higher reading ability was a significant predictor of higher coherence between the right parietal region (seed sensor) and the right temporo-occipital region. (b) A seed sensor was selected in the right temporal region. Higher reading ability was a significant predictor of higher coherence between the right temporal region (seed sensor) and the right frontal, the right parietal and the right temporo-occipital regions. The β values are presented for P < 0.05. The yellow star indicates the seed sensor. The open circles indicate the remaining 150 sensors. The open circles with bold lines indicate the sparse alignment of the MEG sensors for the first analysis in the present study. L = left; R = right.

Figure 6. The t-values of intrahemispheric coherence for the (a) left and (b) right hemispheres between children with ASD (n = 26) and TD children (n = 26).

Positive values represent greater levels in the ASD group than in the TD group. The t-values are presented for P < 0.05. F = selected sensor in the frontal region; C = central; P = parietal; O = occipital; and T = temporal. *P < 0.00056.