Brain-speech tracking in noisy conditions: towards the identification and remediation of dyslexia.

ended

Dyslexia is a developmental disorder leading to reading difficulties. It affects 5–12 % of children and young adults. Unfortunately, we still lack efficient and cost effective methods to identify and remedy this disorder. Dyslexia appears to be frequently linked to hindered phonological processing at the cortical level, with drastic consequences in the presence of noise. The overarching goal of this project is to better understand cortical speech processing in the presence of noise, in order to provide novel identification and remediation methods for dyslexia. Magnetoencephalography and electroencephalography studies have uncovered the phenomenon of brain-speech tracking, that is, the tracking of continuous speech sounds by cortical activity. This tracking is suggested to reflect speech sound chunking and parsing mechanisms, and is altered in dyslexic readers. Importantly, it can be used to evaluate brain capacity to track a sound stream of interest in the presence of noise. Given that individuals’ capabilities to discriminate speech in noisy conditions improve until age ~12, we propose, as a first step, to characterize brain-speech tracking in the presence of noise 1) across the normal development and 2) in children with dyslexia. To modulate task difficulty, we will use several types of noise (from white noise to babble), with or without visual information of the speaker’s lip movements. We will then attempt to predict subjects’ reading skills based on their brain-speech tracking parameters (i.e. their fingerprint of brain-speech tracking capabilities). Finally, we will evaluate whether neurofeedback sessions can sustainably boost brain-speech tracking. These developments are instrumental to the realization of future studies intended to restore the integrity of brain-speech tracking capabilities, with the aim of alleviating the reading deficits of dyslexic readers.