[TS-3.3] Dyslexia as a dis-order: The SOLID hypothesis

Bogaerts, L. 1 , Szmalec, A. 2 , Hachmann, W. M. 3 , Page, M. P. 4 & Duyck, W. 1

1 Ghent University, Ghent, Belgium
2 Université Catholique de Louvain, Louvain-La-Neuve, Belgium
3 University of Trento, Rovereto, Italy
4 University of Hertfordshire, Hatfield, UK

The present paper introduces the SOLID (Serial-Order Learning Impairment in Dyslexia) hypothesis. This novel hypothesis provides an integrative account of dyslexia: it reconciles the dominant theoretical views under the assumption that dyslexia and its variety of related linguistic and nonlinguistic dysfunctions may be traced back to a central, specific impairment of serial-order learning. The SOLID hypothesis is supported by a triple-session experiment in which participants with dyslexia and matched controls memorized sequences of syllables through a Hebb repetition protocol. Memorization and lexical engagement of the repeated sequences was tested immediately, 24h, and one month after Hebb learning. Our results demonstrate that people with dyslexia are fundamentally impaired in the acquisition of serial-order information, leading to impoverished lexical representations.