Visual spatial attention and developmental reading disorder: A longitudinal study

Although developmental dyslexia is often described as the result of a selective phonological deficit, visual magnocellular-dorsal (M-D) deficit hypothesis finds an increasing consent. Recent longitudinal studies pointed out that the M-D pathway plays a key role in the earliest and crucial reading acquisition phase. However, those studies do not address the exact neurocognitive mechanisms that lead from a low level impairment to a reading acquisition disorder. Grapheme–phoneme mapping requires, in addition to awareness of speech sounds, the attentional parsing of the letters strings into their graphemes. In particular, orienting of attention—mainly controlled by the M-D pathway—through letters strings, might represent the link between M-D pathway efficiency and reading acquisition outcome. To investigate this hypothesis, we measured in preschoolers the efficiency in orienting visual attention to a brief spatial exogenous cue. The prereaders were followed up and classified as poor or normal readers on the base of their reading abilities development during the first grade of primary school. Both linear and logistic regressions suggest that efficiency in orienting of visual attention is an effective predictor of reading acquisition outcome. These results support the hypothesis of a causal link between a spatial attention deficit and developmental dyslexia.