The Role of High-Level Vision in Reading Ability: Is Visual Expertise an Instrumental Factor in Reading?

Abstract

The high-level visual dysfunction hypothesis suggests that reading difficulties might partially derive from impairments in high-level regions in the ventral visual stream. Prior research substantiates this view by demonstrating that dyslexics experience hypoactivity in the visual word form area (VWFA) and the fusiform face area (FFA) in the ventral visual stream and that some individuals with dyslexia experience difficulties in visual-individuation object-recognition tasks that are reliant on these brain regions. However, it is not yet known whether difficulties in visual processing are a cause or an effect of poor reading ability. Previous studies on adults suggest that visual expertise is a contributing factor in dyslexia and plays an instrumental role in the hypoactivation of the VWFA and FFA. Consequently, it is important to examine the role of high-level vision in reading before individuals reach different levels of reading experience. The aim of the present study was to explore the relation between reading ability and visual object recognition among children in the fourth grade. In this work, a game-format test on object recognition was adapted for 16 Icelandic children to measure the recognition of a non-expertise category (houses) and an expertise category (faces). The results of this study point to a possible correlation between reading ability and house recognition, although this relationship was found to disappear after controlling for attention-deficit/hyperactivity disorder (ADHD) symptoms. The results showed no correlation between reading ability and face recognition among the children, which is inconsistent with the high-level visual dysfunction hypothesis, and also runs counter to the expertise hypothesis. These results indicate that the visual recognition of complex objects, like houses, might play a part in reading ability. However, due to the small sample size of this work, additional research is needed to explore this issue further.