Search Abstracts | Symposia | Slide Sessions | Poster Sessions
Compensatory Connectome Reorganization in Children with Cochlear Implants: Insights from Naturalistic fNIRS Imaging
Poster Session B, Friday, September 12, 4:30 - 6:00 pm, Field House
Aahana Bajracharya1, Mickael LD Deroche2, Jace Wolfe3, Sara Neumann4, René H Gifford4, Nabin Koirala1,5, Vincent L Gracco1; 1Yale University, 2Concordia University, 3Oberkotter Foundation, 4Hearts for Hearing, 5University of Connecticut
Congenital hearing loss and deafness constitute a connectomic disorder characterized by disrupted cortical-cortical connections, fundamentally altering brain organization (Kral et al., 2016). Such disruptions significantly influence the development of cortical networks and can have long-term implications for language and cognitive development. Hearing intervention such as cochlear implantation initiates the reorganization of the connectome, particularly in auditory and language-related networks. However, the extent and nature of this neuroplastic reorganization and its impact on higher level cognitive domains such as multisensory integration, attention, and memory remains poorly understood. A key limitation is the lack of dynamic, network-level measurements under ecologically valid conditions that engage multiple higher-order cognitive processes simultaneously. In this study, we measured whole brain activity using functional near-infrared spectroscopy (fNIRS) in children with CIs, to investigate neural response during movie viewing. The participants included 75 children (Ages 7 – 17), of whom 50 were children with CIs (CI, mean age = 11.5 ± 2.7 years) with severe to profound congenital bilateral hearing loss, and 25 were children with typical hearing (TH, mean age =12.1 ± 3.1 years). fNIRS data were collected using the NIRScout system (760 nm and 850 nm) with a whole-head montage consisting of 39 sources and 31 detectors, resulting in a total of 122 channels. All participants viewed the same 10-minute clip from the animated children's movie Despicable Me. Pairwise correlation analyses of the time series were performed between regions of interest in frontal, temporal, parietal, and occipital areas of both hemispheres. In addition, we examined connectivity for different parts of the movie clip – chosen to contain contrasting language and non-language (music, minion vocalizations) audio-visual stimulation to assess the effects of acoustic, linguistic and cognitive contrasts. Distinct intra- and inter-hemispheric connectivity patterns differentiated the groups during language segment. TH showed strong bilateral parietal connectivity, which was weaker in CI. CI exhibited moderate bilateral frontal correlations absent in TH. Left occipital-parietal connectivity was strong in TH but absent in CI, which instead showed negative correlations between left parietal and frontal regions. Inter-hemispherically, TH displayed strong occipital-parietal and temporal-parietal connections, and negative temporal-occipital correlations, all diminished or absent in CI. CI showed unique negative parietal-frontal inter-hemispheric connectivity. During the non-speech movie segment, TH maintained strong bilateral parietal connectivity, while CI relied more on left occipital and right occipital-temporal connections, with further reduced parietal involvement. TH also showed a strong parietal-frontal negative correlation. In summary, children with typical hearing show efficient, specialized inter- and intra-hemispheric connectivity supporting multimodal speech integration. In contrast, children with CIs exhibit compensatory reorganization, characterized by reduced parietal integration, increased reliance on frontal and occipital regions, and atypical inter-hemispheric dynamics. These patterns suggest altered cortical resource allocation and increased cognitive load in children with cochlear implants. Our findings demonstrate that naturalistic movie viewing with fNIRS is a viable and informative paradigm for assessing functional brain organization in CI users. This approach holds promise for guiding evidence-based interventions aimed at optimizing speech and language outcomes.
Topic Areas: Disorders: Developmental, Multisensory or Sensorimotor Integration