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Altered resting-state oscillations in children with developmental dyslexia
Poster Session E, Friday, October 2, 11:00 am - 1:00 pm, Wangari Maathai
This poster is part of the Sandbox Series.
Jiaqi Mao1,2, Nicola Molinaro1,3, Mikel Lizarazu1; 1BCBL, Basque Center on Cognition, Brain and Language, San Sebastian, Spain, 2University of the Basque Country (UPV/EHU), Spain, 3Ikerbasque, Basque Foundation for Science, Bilbao, Spain
Developmental dyslexia (DD) is associated with atypical functional activity in left-lateralized reading circuits and with altered neural oscillatory dynamics. Beyond examining isolated brain regions, increasing research has investigated alterations in functional connectivity. Previous resting-state studies have reported atypical alpha-connectivity within fronto-temporo-parietal networks in DD, suggesting that the dyslexia-related network reorganization involves not only spatial alterations but also changes in temporal dynamics. Resting-state designs investigating intrinsic functional changes in DD are particularly suitable for younger preliterate children. In addition, recent work using spectral fingerprinting provides a promising framework for characterizing such alterations. Compared with conventional regional analyses, MEG-based spectral fingerprints provide temporal dynamic estimates of how an oscillatory regime dominates resting activity during electrophysiological recordings, as well as estimates of its power amplitude and duration at the cortical level. By focusing on regional spectral components across frequency bands, the fingerprinting approach may reveal potential frequency- and region-specific markers of DD. The present study uses resting-state MEG to examine intrinsic neural alterations in DD. Five-minute resting-state recordings were obtained from 20 children with DD and 22 age-matched typical readers (TR). Spectral estimates were extracted from 28 pairs of cortical regions and their homologues, selected based on previous resting-state literature of DD. In addition, similarity analyses were conducted to examine the organization of large-scale functional networks based on similar spectral profiles across regions. Source-level analyses revealed group differences in regional spectral profiles. Relative to TR, children with DD showed reduced alpha-power at ~10 Hz in the right lingual gyrus and right calcarine fissure. Furthermore, DD was associated with spectral peaks at lower frequencies in the left fusiform gyrus (3.0 Hz in DD vs. 7.0 Hz in TR), and with higher-frequency peaks in the right middle cingulate cortex (8.5 Hz in DD vs. 7.0 Hz in TR) and left insula (22.5 Hz in DD vs. 1.5 Hz in TR). At the network level, spectral similarity analysis revealed a less differentiated organization of resting-state networks in DD, characterized by two widespread bilateral clusters with similar spectral profiles, compared with four specialized clusters in TR. Overall, the present findings suggest that DD is characterized by atypical intrinsic oscillatory organization at both regional and large-scale network levels. Altered occipital alpha activity together with reduced differentiation of spectral similarity networks may reflect less specialized functional organization and atypical inhibitory or attentional control mechanisms at rest. These results converge with previous evidence of altered lateralization and neural synchronization in dyslexia, while further emphasizing the importance of resting-state spectral dynamics for understanding the neurophysiological basis of DD. Such intrinsic neural markers may ultimately prove useful for informing earlier identification and intervention approaches.
Topic Areas: Disorders: Developmental, Language Development/Acquisition