Researcher Lecture by Dr. Mickael Deroche.

Exploration of brain plasticity in children with cochlear implants using electroencephalography and functional near-infrared spectroscopy

Abstract: Cochlear implants restore a sense of hearing to profoundly deaf individuals. For children who were born deaf, these devices have proven incredibly useful: many acquire spoken language relatively normally and enter mainstream schools. However, global outcomes in terms of academic achievements differ widely between children and we are trying to understand why, by looking at their brain. In this project, we recruited over 50 children (grade 3 to 12), implanted early in life (20 months old) or slightly later (30 months). Along with audiological assessments, all children completed a battery of tests to evaluate their language skills and their reading skills. Furthermore, we recorded their cortical activity using (sequentially) EEG and fNIRS in response to 1) visual processing (checkerboard and visual speech), 2) auditory processing (oddball noises and auditory speech), 3) somatosensory/motor processing (joystick with/without vibration), 4) multi-sensory processing (audiovisual speech and words/nonwords reading and listening), and 5) resting state networks and connectivity (inscapes, or emotional video clip). This presentation will review our findings to date, highlighting evidence for maladaptive cross-modal plasticity caused by a delayed age at (first) implantation.

Short bio: Dr. Deroche is interested in hearing and cognition, using behavioral and neurophysiological techniques. He is originally from France, coming from an engineering background in acoustics. In 2009, he completed his PhD in Cardiff University studying the use of pitch in cocktail-party situations. From 2010 to 2015, he worked at the University of Maryland and at Johns Hopkins, documenting the challenges that users of cochlear implants face with pitch perception and how they translate into further deficits in music and language. In 2015, he moved to Montreal and worked in different centers on a number of projects spanning auditory masking, emotion processing, sensorimotor integration, cognitive load and short-term memory in listeners with impoverished hearing and other populations of interest (musicianship, stuttering). As of 2019, he is Assistant Professor in the Psychology Department at Concordia University. His laboratory investigates processing of speech and music, in healthy and pathological hearing.