The effects of inter-letter spacing in visual-word recognition: Evidence with young normal readers and developmental dyslexics

Recent research has demonstrated that slight increases of inter-letter spacing have a positive impact on skilled readers' recognition of visually presented words. In the present study, we examined whether this effect generalises to young normal readers and readers with developmental dyslexia, and whether increased inter-letter spacing affects the reading times and comprehension of a short text. To that end, we conducted a series of lexical decision and continuous reading experiments in which words were presented with the default settings or with a small increase in inter-letter spacing. Increased spacing produced shorter word identification times not only with adult skilled readers (Experiment 1), but also with young normal readers (Grade 2 and Grade 4 children; Experiment 2) and, even to a larger degree, with readers with dyslexia (Experiments 3 and 4). These experiments suggest that slight increases in inter-letter spacing would improve the readability of texts aimed at children, especially those with dyslexia.

► We examine whether slight increases in inter-letter spacing produce a beneficial effect for young readers.
► Results showed a beneficial effect of small increases of inter-letter spacing.
► These findings may have important implications for the choice of inter-letter spacing in children books.