Resting-state alpha power is selectively associated with autistic traits reflecting behavioral rigidity

Abstract

Previous research suggests that variation in at-rest neural activity correlates with specific domains of the ASD phenotype; however, few studies have linked patterns of brain activity with autistic trait expression in typically developing populations. The purpose of this study was to examine associations between resting-state electroencephalography (EEG) and three domains of the broader autism phenotype (social interest, rigidity, and pragmatic language) in typically developing individuals. High-density scalp EEG was recorded in thirty-seven typically developing adult participants (13 male, aged 18-52 years). The Broad Autism Phenotype Questionnaire (BAP-Q) was used to measure autistic trait expression. Absolute alpha power (8-13 Hz) was extracted from eyes-closed epochs using spectral decomposition techniques. Analyses revealed a specific positive association between scores on the BAP-Q Rigidity subscale and alpha power in the parietal scalp region. No significant associations were found between alpha power and the BAP-Q Aloofness or Pragmatic Language subscales. Furthermore, the association between EEG power and behavioral rigidity was specific to the alpha frequency band. This study demonstrates that specific traits within the broader autism phenotype are associated with dissociable patterns of at-rest neural activity.

Figure 1

(A) Scalp-wide distribution of absolute alpha power. (B) Comparison of absolute alpha power across the frontal (Fz), central (Cz) and parietal (Pz) ROIs.

Figure 2

(A) Correlations between BAP-Q subscale scores and absolute alpha power at each electrode in the parietal ROI. (B) Visual comparison of the correlation between each BAP-Q subscale (Rigidity, Aloofness, and Pragmatic Language) and alpha power at individual electrodes within the parietal ROI. Dotted lines represent the average correlation across the ROI. **p < 0.01.

Figure 3

Left: Heat map depicting the correlation between absolute alpha power and BAP-Q Rigidity scores at each electrode in the parietal ROI. Right: Association between mean absolute alpha power across the parietal ROI and BAP-Q Rigidity scores.