Research project: Brain connectivity modelling in cochlear implants

The brain organisation can be quantified by connectivity measures, which may provide the strength, direction, and timing information on the connection between brain areas. One approach to measure brain connectivity is Dynamic Causal Modelling (DCM). DCM is a biophysically informed model which models the strength of couplings between two areas and the effect of one area over itself based on a neural mass model adapted from the Jansen neuronal model. DCM assumes that a designed input is perturbing the model and its output is measured as the brain response recorded in surface EEG, MEG or fMRI. The parameters of the model include inter- and intra-area coupling coefficients, conduction delays, and input parameters and are estimated employing a Bayesian framework.

This research project aims to investigate the effective brain connectivity in normal people and patients with unilateral and bilateral cochlear implants using surface EEG during tone, word and sentence perception. We aim to reveal the brain connectivity patterns in CI users, the change over time after implantation and the contribution of bilateral implantation to bilateral brain interaction. The research not only will contribute to better understanding of the underneath activities of the brain in speech perception but also may provide useful information about how to help CI-users benefit most from their implants. Furthermore, it can be a predictive measure of how well a CI might be of benefit to patients after implantation.