title: Altered patterns of directed connectivity within the reading network of dyslexic children and their relation to reading dysfluency.
abstract: Reading is a complex cognitive skill subserved by a distributed network of visual and language-related regions. Disruptions of connectivity within this network have been associated with developmental dyslexia but their relation to individual differences in the severity of reading problems remains unclear. Here we investigate whether dysfunctional connectivity scales with the level of reading dysfluency by examining EEG recordings during visual word and false font processing in 9-year-old typically reading children (TR) and two groups of dyslexic children: severely dysfluent (SDD) and moderately dysfluent (MDD) dyslexics. Results indicated weaker occipital to inferior-temporal connectivity for words in both dyslexic groups relative to TRs. Furthermore, SDDs exhibited stronger connectivity from left central to right inferior-temporal and occipital sites for words relative to TRs, and for false fonts relative to both MDDs and TRs. Importantly, reading fluency was positively related with forward and negatively with backward connectivity. Our results suggest disrupted visual processing of words in both dyslexic groups, together with a compensatory recruitment of right posterior brain regions especially in the SDDs during word and false font processing. Functional connectivity in the brain's reading network may thus depend on the level of reading dysfluency beyond group differences between dyslexic and typical readers.
authors.affiliation: Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Oxfordlaan 55, 6229EV Maastricht, Netherlands; Maastricht Brain Imaging Center (M-BIC), Oxfordlaan 55, 6229EV Maastricht, Netherlands. Electronic address: gojko.zaric@maastrichtuniversity.nl.
authors.forename: Gojko
authors.initials: G
authors.lastname: Žarić
authors.affiliation: Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Oxfordlaan 55, 6229EV Maastricht, Netherlands; Maastricht Brain Imaging Center (M-BIC), Oxfordlaan 55, 6229EV Maastricht, Netherlands. Electronic address: joao.correia@maastrichtuniversity.nl.
authors.forename: João M
authors.initials: JM
authors.lastname: Correia
authors.affiliation: Department of Developmental Psychology, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam, Netherlands; Rudolf Berlin Center, Valckenierstraat 65-67, 1018 XE Amsterdam, Netherlands. Electronic address: G.FragaGonzalez@uva.nl.
authors.forename: Gorka
authors.initials: G
authors.lastname: Fraga González
authors.affiliation: Department of Developmental Psychology, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam, Netherlands; IWAL Institute, Prins Hendrikkade 84, 1012 AE Amsterdam, Netherlands. Electronic address: jurgentijms@iwal.nl.
authors.forename: Jurgen
authors.initials: J
authors.lastname: Tijms
authors.affiliation: Department of Developmental Psychology, University of Amsterdam, Nieuwe Achtergracht 129, 1018 WS Amsterdam, Netherlands; Amsterdam Brain and Cognition, University of Amsterdam, Nieuwe Achtergracht 129B 1018WS Amsterdam, The Netherlands. Electronic address: M.W.vanderMolen@uva.nl.
authors.forename: Maurtis W
authors.initials: MW
authors.lastname: van der Molen
authors.affiliation: Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Oxfordlaan 55, 6229EV Maastricht, Netherlands; Maastricht Brain Imaging Center (M-BIC), Oxfordlaan 55, 6229EV Maastricht, Netherlands.
authors.forename: Leo
authors.initials: L
authors.lastname: Blomert
authors.affiliation: Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Oxfordlaan 55, 6229EV Maastricht, Netherlands; Maastricht Brain Imaging Center (M-BIC), Oxfordlaan 55, 6229EV Maastricht, Netherlands. Electronic address: m.bonte@maastrichtuniversity.nl.
authors.forename: Milene
authors.initials: M
authors.lastname: Bonte
mesh_terms: D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D002648:Child; D004410:Dyslexia / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D010775:Photic Stimulation / Q000379:methods*; D011897:Random Allocation; D011930:Reaction Time / Q000502:physiology; D011932:Reading
keywords: Developmental dyslexia; Directed functional connectivity; Directed transfer function; Reading fluency; Visual word recognition