Search Abstracts | Symposia | Slide Sessions | Poster Sessions
EEG hyperscanning of naturalistic caregiver-child interaction with limited electrodes: implications for language and social development
Poster C31 in Poster Session C, Thursday, October 1, 10:45 am - 12:45 pm, Wangari Maathai and Lise Girardin
This poster is part of the Sandbox Series.
Zhaohan Jiang1, Nikolay Novitskiy1, Patrick Wong1; 1The Chinese Uuniversity of Hong Kong
[Introduction] Caregiver-child brain synchrony is a potential candidate neural marker for early language and social development. The synchrony may indicate the quality of joint engagement in caregiver-child interaction, which is key to a child’s language learning. However, achieving robust synchrony results is challenging. A functional region in adults is not guaranteed to align with the same one in infants, due to challenges of identifying developmental homology (Turk-Browne & Aslin, 2024). Currently, there is a major gap in early language studies with hyperscanning tools. Even teenager/adult studies showed inconsistent and complex inter-brain patterns under different tasks, calling for a systematic investigation that requires multiple channels (usually a cap), which is less feasible with infants/toddlers and in naturalistic settings. Therefore, the current study proposed an adaptive measurement for caregiver-child interaction: fewer electrodes and directional connectivity methods. [Method] 27 Chinese caregiver-child dyads watched 5-minute child-friendly cartoon clips (17.3 months ± 2.6 months). In the engagement section (2.5 mins), a dyad watched the same movie on the same laptop, while in the disengagement section (2.5 mins), they watched different movies on different laptops. A camera was used to record their looking directions. To reduce the number of electrodes, we selected C3 and C4 as representative channels from the left/right hemispheres, because the central areas exhibit the strongest adult-to-infant connectivity and greatest resilience to artifacts (Leong et al. 2017). EEG data were recorded at a 2048 Hz sampling rate, downsampled to 256 Hz, low-passed <16 Hz, and segmented into 1-second epochs. Epochs with amplitudes >80 μV were excluded. We focused on infant theta (3-6 Hz) and alpha (6-9 Hz). Two analysis approaches were adopted. Adjusted Circular Correlation (Ccorr) measures non-directional coupling with less spurious coupling than phase-locking values (Zimmermann et al. 2024); Generalized Partial Directed Coherence (GPDC) measures directional connectivity, i.e., the degree of one channel predicting/influencing the other. A permutation test is conducted as a baseline for significance check (paired t tests with Benjamini–Hochberg FDR-corrected, one-tailed, p<0.05), where a surrogate dataset is generated by randomly shuffling the epochs 1,000 times within each condition for each dyad to disturb the temporal correspondence. [Results] With limited electrodes (C3/C4), traditional non-directional coherence showed indistinguishable synchrony between different engagement conditions. However, directional connectivity across channels (Grand GPDC) revealed distinct patterns. For child-to-caregiver coupling, children showed a stronger influence on caregivers when they were watching the same movie at both theta and alpha bands; whereas for caregiver-to-child coupling, caregivers showed a stronger influence on their children when they were watching different movies (paired t-tests, P<0.05 and P<0.001). The same directional patterns still hold after excluding interactional moments (only watching moments remained). A low ratio of interaction time (3.1% ± 3.52%) and epochs adjacent to interaction onset/offset (1.15% ± 1.27%) further imply that passive movie watching alone can elicit inter-brain effects. [Conclusion] With fewer electrodes, directional methods reveal divergent caregiver-child coupling patterns, which were not observed by the commonly adopted non-directional methods. These findings further support the proposed feasible approach for early language and social development studies.
Topic Areas: Language Development/Acquisition, Methods