biostudies-literatureChung HNIDCD NIH HHSNIH HHS58https://www.ebi.ac.uk/biostudies/studies/S-EPMC12482115biostudies-literatureUnknown17(1)<h4>Background</h4>Restricted and repetitive behaviors (RRB) are core features of autism but are also observed in typical development. Our understanding of the neural underpinnings of RRBs is limited. Given that excitation-inhibition (E/I) balance may underlie RRBs, we aimed to evaluate the relationship between aperiodic exponent (as a proxy of E/I balance) and changes in RRBs over time in infants with and without elevated likelihood of autism.<h4>Methods</h4>Resting-state EEG data were collected from 12-to-14-month-old infants and aperiodic exponent was calculated. Parent-reported RRBs were obtained using the Repetitive Behavior Scale-Revised questionnaire to measure the severity and change in RRBs from 12-to-36 months. Multiple linear regressions were conducted to assess relationships beJournal of neurodevelopmental disordersThe association between infant EEG aperiodic exponent and the trajectory of restricted and repetitive behaviors for toddlers with and without autism.PMC12482115R01-DC010290R03 DC007983K23DC07983R01 DC010290Job Said AWilkinson CLChung HTager-Flusberg HNelson CAfalseThe association between infant EEG aperiodic exponent and the trajectory of restricted and repetitive behaviors for toddlers with and without autism.<h4>Background</h4>Restricted and repetitive behaviors (RRB) are core features of autism but are also observed in typical development. Our understanding of the neural underpinnings of RRBs is limited. Given that excitation-inhibition (E/I) balance may underlie RRBs, we aimed to evaluate the relationship between aperiodic exponent (as a proxy of E/I balance) and changes in RRBs over time in infants with and without elevated likelihood of autism.<h4>Methods</h4>Resting-state EEG data were collected from 12-to-14-month-old infants and aperiodic exponent was calculated. Parent-reported RRBs were obtained using the Repetitive Behavior Scale-Revised questionnaire to measure the severity and change in RRBs from 12-to-36 months. Multiple linear regressions were conducted to assess relationships be2025-01-01T00:00:00Z2025 Sep2026-06-04T05:05:45.549Z2026-06-03T03:07:45.977ZS-EPMC124821154102378610.1186/s11689-025-09651-3