Research Council Back-up mandate Eva Staels - Evaluating the visual attention span hypothesis as a causal explanation for dyslexia and as a new direct measure of parallel processing

According to the VAS hypothesis the number of visual elements one can process simultaneously defines our reading ability. The goal of this research project is to investigate if a reduced VAS is causally related to reading problems and if the relationship is also to be found using nonverbal material and report.
Readers shift from serially processing words letter by letter to processing words in parallel. These processes of reading words represent the two routes in the dual-route model of reading. Until now reading ability has only been measured by accuracy and speed of reading words and pseudowords. To date there is no direct way to measure in which reading ‘stage’ a child is situated. The second
objective of this project is to investigate the VAS as a measure of parallel processing words. The dual-route model of reading has been developed in the context of the English language. English is the most inconsistent alphabetic writing system, which means that the association between written and spoken forms of words are complex and inconsistent. Using the VAS as a measure of parallel processing will enable us to critically test the dual route model in both deep and shallow orthographies. If the results show that readers in deep
orthographies use the parallel processing route more often than readers in shallow orthographies these readers might be more affected by a VAS deficit. This research project will be the first to study if VAS deficits are correlated with orthographic depth.