British Dyslexia Association 9th International Conference: 'Creating Impact Through Innovation' edition:9 location:Guildford, UK date:27-29 March 2014
In this keynote presentation we will present the results of our recent studies on the contribution of auditory processing and speech perception skills on reading development and on their neural basis.
Our longitudinal project demonstrated that children with dyslexia have pre-reading deficits in auditory processing, speech perception and phonology, but more importantly, that basal auditory temporal processing and speech perception in kindergarten uniquely contribute to growth in reading ability (Boets et al., RIDD, 2011).
We investigated structural and functional neural connectivity in the speech perception, phonology and reading network (using DTI and fMRI) and neural auditory processing (using Auditory Steady-State Responses, ASSR) in a sample of adults with dyslexia. DTI results showed specific impairments in the left arcuate fasciculus (important for the sublexical reading route), and not in the left inferior-frontal-occipital fasciculus (important for the lexical reading route) (Vandermosten et al., Brain, 2012). fMRI results confirmed decreased connectivity between cortical regions involved in speech perception (Boets et al., Science, 2013). ASSR results demonstrated decreased neural responses for auditory modulations which are important for phoneme identification (20 Hz) whereas no problems were found for the syllabic-rate (4 Hz). Not only were the phonemic-rate responses in left posterior areas lower, also the functional connection between hemispheres and within the left posterior regions was weaker (Poelmans et al., Ear and Hearing, 2012).