Explainable Exploration of the Interplay between HRV Features and EEG Local Connectivity Patterns in Dyslexia.

Heart Rate Variability (HRV) is a measure of the variation in time between successive heartbeats, reflecting the influence of the au- tonomic nervous system on the heart. It can provide insights into the bal- ance between sympathetic and parasympathetic activity. The relation- ship between autonomic nervous system function, specifically parasym- pathetic activity, and certain learning disorders, including dyslexia, is currently under study. In this paper, we propose the use of explain- able techniques to explore the relationships between HRV markers and local functional brain activity, estimated by cross-frequency coupling (CFC) from electroencephalography (EEG) signals recorded while audi- tory stimuli were applied to 7-year-old children. We analyze EEG data to examine the phase-to-phase brainwave coupling and use machine learn- ing tools such as XGBoost and Shapley values to reveal brain regions that most contribute to different HRV features, with a focus on parasympa- thetic activity. Our findings suggest that HRV features related to stress can explain differential activations in the auditory cortex (Brodmann areas 39 and 40) during auditory stimulation in dyslexic children