The Word Superiority Effect in central and peripheral vision

The Word Superiority Effect (WSE) is a well-known phenomenon in reading research, where words are reported more accurately than single letters or non-words. We report two experiments that investigate the WSE in the central and peripheral visual field, as well as laterality differences in the perception of words and letters, using methods based on the Theory of Visual Attention. The results show a WSE in the central visual field, reflected in mean scores, perception thresholds, and processing speed, whereas the effect is eliminated or reversed in the periphery. This may be caused by crowding, which prevents lexical analysis of a word in the periphery. We conclude that perception of words and letters differs according to location in the visual field. Linking our results to previous studies of crowding effects in patients with reading impairments, we hypothesize that similar mechanisms may limit normal word peripheral processing.