Biology subjects

Wong, P. C. M.

Publications and source records attributed to Wong, P. C. M..

4 recordsLinked to original sources

bioRxiv2026

Auditory tracking magnitude, temporal alignment, and anatomical distribution during wakefulness and propofol-based anesthesia in human sEEG

General anesthesia attenuates auditory responses, but response magnitude alone does not describe how residual activity aligns with sound over time or varies across the brain. We jointly characterized these aspects of auditory tracking using stereoelectroencephalography (sEEG) in 13 patients with drug-resistant epilepsy during wakefulness and clinically defined unresponsiveness under propofol-based anesthesia. The same rhythmic humming sequences were presented at approximately 1.61 Hz in both sessions. During anesthesia, stimulus-rate power showed widespread reductions and phase alignment with the stimulus rhythm was less consistent, although responses remained detectable at some recording channels. During wakefulness, response strength decreased with cortical surface distance from posteromedial Heschl's gyrus; this distance-response relationship was weaker during anesthesia. In a contrastive learning analysis (CEBRA), low-dimensional embeddings derived from anesthesia recordings yielded lower acoustic-envelope decoding accuracy on held-out data and lower consistency across model fits. Together, these findings characterize how attenuated auditory tracking is expressed jointly in response magnitude, temporal alignment, and anatomical distribution.

neuroscience↗

bioRxiv2026

Autistic Children Show Reduced Activity in Left Superior Temporal Cortex in Response to Social-emotional Meaning in Language

Autistic children often differ from non-autistic peers in social interaction, emotional processing, and language communication. While the neural differences between autistic and non-autistic children in processing paralinguistic social-emotional cues, such as emotional prosody, are well-documented, much less is known about how the brain processes the social-emotional meaning carried by the language content itself. In non-autistic adults, the left superior temporal sulcus (STS) and adjacent gyrus show a social-emotional bias, responding more strongly to social-emotional content than to content describing inanimate objects. We investigated whether this bias is present in children and whether it is altered in autistic children. We recruited 78 right-handed children who underwent functional magnetic resonance imaging (fMRI) scanning while listening to sentences describing either people in emotional situations (social-emotional sentences) or non-human objects, events, or concepts (object sentences). After excluding those with excessive head motion, we analyzed data from 58 of them (37 autistic and 21 non-autistic; mean age 10 years). Across the sample as a whole, the left STS responded more strongly to social-emotional sentences than to object sentences, indicating that this social-emotional bias is already present in childhood. Importantly, this bias was reduced in autistic children compared to non-autistic controls, whereas no group difference was observed in general auditory or lexico-syntactic processing. This reduced activity in the left STS in response to social-emotional semantics may contribute to autistic children's social communication challenges.

neuroscience↗

bioRxiv2023

Deficits in neural encoding of speech in preterm infants

Preterm children show developmental cognitive and language deficits that can be subtle and sometimes undetectable until later in life. Studies of brain development in children who are born preterm have largely focused on vascular and gross anatomical characteristics rather than pathophysiological processes that may contribute to these developmental deficits. Neural encoding of speech as reflected in EEG recordings is predictive of future language development and could provide insights into those pathophysiological processes. We recorded EEG from 45 preterm ([≤] 34 weeks of gestation) and 45 full-term ([≥] 38 weeks) Chinese-learning infants 0 to 12 months of (corrected) age during natural sleep. Each child listened to three speech stimuli that differed in lexically meaningful pitch (2 native and 1 non-native speech categories). EEG measures associated with synchronization and gross power of the frequency following response (FFR) were examined. ANCOVAs revealed no main effect of stimulus nativeness but main effects of age, consistent with earlier studies. A main effect of prematurity also emerged, with synchronization measures showing stronger group differences than power. By detailing differences in FFR measures related to synchronization and power, this study brings us closer to identifying the pathophysiological pathway to often subtle language problems experienced by preterm children.

neuroscience↗

bioRxiv2021

Separate neural dynamics underlying the acquisition of different auditory category structures

Current models of auditory category learning argue for a rigid specialization of hierarchically organized regions that are fine-tuned to extracting and mapping acoustic dimensions to categories. We test a competing hypothesis: the neural dynamics of emerging auditory representations are driven by category structures and learning strategies. We designed a category learning experiment where two groups of learners learned novel auditory categories with identical dimensions but differing category structures: rule-based (RB) and information-integration (II) based categories. Despite similar learning accuracies, strategies and cortico-striatal systems processing feedback differed across structures. Emergent neural representations of category information within an auditory frontotemporal pathway exclusively for the II learning task. In contrast, the RB task yielded neural representations within distributed regions involved in cognitive control that emerged at different time-points of learning. Our results demonstrate that learners neural systems are flexible and show distinct spatiotemporal patterns that are not dimension-specific but reflect underlying category structures. SignificanceWhether it is an alarm signifying danger or the characteristics of background noise, humans are capable of rapid auditory learning. Extant models posit that novel auditory representations emerge in the superior temporal gyrus, a region specialized for extracting behaviorally relevant auditory dimensions and transformed onto decisions via the dorsal auditory stream. Using a computational cognitive neuroscience approach, we offer an alternative viewpoint: emergent auditory representations are highly flexible, showing distinct spatial and temporal trajectories that reflect different category structures.

bioinformatics↗