The impairment of the visual-spatial attention in Chinese children with dyslexia: A cognitive deficit or a developmental delay?

Although emerging evidence suggests that developmental dyslexia shows deficits in visual-spatial attention, previous studies have also confirmed that visual-spatial attention may be particularly important for reading among Chinese children with dyslexia. However, the visual-spatial attention deficit of dyslexic Chinese children has not been fully investigated. Therefore, the present study employed the cue-target paradigm and examined whether the earlier processing of visual-spatial attention deficit would be found in Chinese children with dyslexia. More importantly, we combined read level match design to determine the process of visual-spatial attention in Chinese children with dyslexia related to developmental delay or cognitive deficits. Results showed that developmental dyslexia (DD) group exhibited no cueing effect in the cue-target tasks when the stimulus onset synchronies (SOAs) were set to 100 ms, as compared with the children's chronological age (CA). With the cueing effect as the index, we also observed that the CA group had a robust facilitation effect in early processing of visual-spatial attention. Importantly, the DD group presented an impaired facilitation effect as the same reading level (RL) group controls when SOAs were 100 ms and 350 ms. These findings suggested that impaired facilitation effect in Chinese dyslexic children is due to a developmental delay.