## 5 Conclusions  
We found that the cognitive task amplifies even the small individual differences in functional connectivity characteristics among 8-year-old children and also predicts developmental problems in a sex-dependent manner, which aligns with findings from fMRI task data [47]. Notably, our approach outperformed models constructed from resting-state data [47]. Although this study included a small sample, similar to [PERSON] et al. [45], we observed that differences in functional capacity between sensorimotor and association cortices partly stem from regional variations in functional connectivity profiles. These differences are influenced by connectivity maturation during brain development [10]. During development, sensory-motor networks exhibit increasing connectivity and become integrated with other networks, while associative networks show decreased connectivity and remain more segregated from other networks during childhood [45]. The different development of functional integration and segregation can be related to the variability of functional connectivity development between boys and girls with DD. Furthermore, the development of functional connectivity varies even at the level of sensorimotor networks in boys with DD and does not demonstrate the expected age-related maturation effect. **Supplementary Materials:** The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app15041797/s1](https://www.mdpi.com/article/10.3390/app15041797/s1)]([https://www.mdpi.com/article/10.3390/app15041797/s1](https://www.mdpi.com/article/10.3390/app15041797/s1)), Figure S1. Experimental diagram of the contrast discrimination of low-spatial-frequency (LSF) illusion, presented in a pseudorandomized sequence. The illusions were flickering sinusoidal gratings with a spatial frequency of two cycles per degree and a high temporal frequency 15 Hz of counter phase flicker. The left hand was used to respond to a low-contrast LSF illusion and the right hand to respond to a high-contrast illusion. A short beep signaled the end of each realization. The inter trial intervals (ITI) were 1.5-3.5 s. A fixation cross was presented during the ITI, marking the beginning of each realization; Figure S2. The positions of the 40 EEG sensors are according to the international systems 10/20 (green circles) and 10/10 (yellow circles); Figure S3. Electrode positions and cytoarchitectural areas according to Brodmann; Figure S4. Mean of global measures \(\varphi\), \(\Delta\)C, \(\Delta\)L of frequency \(\delta\), \(\delta\), \(\alpha\), \(\delta\)1, \(\delta\)2, \(\gamma\)1, and \(\gamma\)2 networks for all Controls (gray) and all DD (black) under low-contrast LSF illusion (upper panel) and under high-contrast LSF illusion (lower panel). Only those frequency ranges are presented where there is a significant difference for at least one of the global measures (marked with bold text in Tables S3 and S4); Table S1. Psychological scores of the groups in standard scores (mean \(\pm\) s.d. ; second and fifth column). The statistics (F, p) of boys with DD vs. girls with DD (third, fourth column); control boys vs. girls (sixth, seventh columns); statistics of controls vs. group with DD (eighth and ninth columns); Table S2. Statistical comparisons of the means of behavioral parameters (p, \(\chi^{2}\), Kruskal-Wallis test; significance level, \(p\) < 0.05; number of correct trials for each condition: 525 for Control, 792 for children with DD) in the LSF illusion. Nonparametric size effect (analog of [PERSON]'s d): small effect: Q = 0.1; medium effect: Q = 0.3; large effect: Q = 0.5 [40; 41; 42]; Table S3. Statistical comparison of global measures \(\varphi\), \(\Delta\)C, \(\Delta\)L (means \(\pm\) s.e. ; Kruskal-Wallis Test: \(\chi^{2}\) statistic, \(p\)-value, significance threshold 0.0167) of frequency \(\delta\), \(\delta\), \(\alpha\), \(\delta\)1, \(\delta\)2, \(\gamma\)1, and \(\gamma\)2 networks for Control and DD for low-contrast LSF illusion.