Developmental dyslexia is a heterogeneous disorder that emerges during a child's development, affecting their learning trajectory and presenting with a variety of symptoms, primarily difficulties in written language and especially in reading. Individuals with dyslexia are characterized by difficulties in word recognition and decoding despite their normal intellectual capacity, adequate educational opportunities, and the absence of sensory or other problems. The aim of the present study was to investigate potential deficits in phonological awareness and processing speed in children with developmental dyslexia. The sample consisted of 24 students (mean age 9.6 years, range 8.8-10.6 years), who were divided into two groups. The first group included 14 students who had been diagnosed with dyslexia by a public institution. The second group, the control group, consisted of 14 typically developing children matched for gender and age with the children in the experimental group. To assess phonological awareness, participants were tested on reading Greek pseudowords, and to evaluate processing speed, they were tested on coding tasks. The results showed statistically significant differences between the performance of the two groups in both administered tasks. These findings are consistent with the majority of research indicating deficits in phonological awareness and processing speed, confirming the double-deficit hypothesis, according to which individuals with dyslexia exhibit deficits in both phonology and processing speed.

Keywords: Developmental dyslexia, double-deficit hypothesis, shallow orthography.