Research › Learning & Development
Resting EEG effective connectivity at the sources in developmental dysphonetic dyslexia. Differences with non-specific reading delay
STS Instructor Authored by Giuseppe A. Chiarenza
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Study at a glance
- Area
- Learning & Development
- Study type
- Observational study
- Authors
- Bosch-Bayard J, Girini K, Biscay RJ, Valdes-Sosa P, Evans AC, Chiarenza GA
- Journal
- International Journal of Psychophysiology
- Year
- 2020
- Participants
- 227 (184 dysphonetic dyslexia, 43 non-specific reading delay)
- Population
- Children
- Protocol
- resting QEEG source analysis with directed (isolated effective) coherence among 17 regions
Key findings
- The left calcarine (primary visual) region acted as a stronger information hub in dysphonetic dyslexia
- The left rolandic operculum was the more active hub in the reading-delay group
- In dyslexia, outflow from the visual hub reached right postcentral, left paracentral, right angular and right supplementary motor areas
- Much of this flow occurred in slow bands, interpreted as support for a timing-deficit model of dyslexia
Children with dysphonetic dyslexia (difficulty linking letters to sounds) were compared with children whose reading was simply delayed, to test the idea that dyslexia involves poorly timed communication between brain areas. Resting EEG was mapped to its cortical sources, and the direction of information flow among 17 regions was estimated and compared statistically between groups. The two groups relied on different hub regions, and in the dyslexia group a left visual-cortex hub sent information to several sensory, motor and parietal areas across most frequency bands, including slow delta and theta, which the authors read as a sign of less efficient signalling.