The mirror reflects more for d than for b: Right asymmetry bias on the visual recognition of words containing reversal letters

Abstract

Research has shown that recognizing words that contain reversal letters (e.g., b/d) is more difficult than recognizing words that do not contain them. Although none of the current computational models of visual word recognition can account for this effect, it was recently suggested that it may arise from lateral inhibition connections that, at the letter level of processing, can be established between reversal nodes. However, because in writing left-faced letters (e.g., d) are more prone to be reversed into right-faced letters (e.g., b) than the inverse, we hypothesized that the directionality of the reversal letters could modulate the magnitude of the mirror-letter interference effect. In this study, we directly tested this hypothesis by using a highly controlled set of European Portuguese (EP) words containing only either the mirror-letter b or the mirror-letter d in three lexical decision (go/no-go) masked priming experiments conducted with EP adult skilled readers (Experiment 1) and two groups of EP developing readers (third-grade children [Experiment 2] and fifth-grade children [Experiment 3]). Results showed that reliable mirror-letter interference effects were observed only for d-words in both adult skilled readers and fifth-grade children, which asks for additional amendments in the current computational models of visual word recognition.