Word frequency does not moderate the degree to which people can selectively attend to parts of visually presented words

Whether attention is allocated to an entire word or can be confined to part of a word was examined in an experiment using a visual composite task. Participants saw a study word, a cue to attend to either the right or left half, and a test word, and indicated if the cued half of the words (e.g., left) was the same (e.g., TOLD-TONE) or different (e.g., TOLD-WINE). Prior research using this task reports a larger congruency effect for low-frequency words relative to high-frequency words but extraneous variables were not equated. In this study (N = 33), lexical (orthographic neighbourhood density) and sublexical (bigram frequency) variables were controlled, and word frequency was manipulated. Results indicate that word frequency does not moderate the degree to which parts of a word can be selectively attended/ignored. Response times to high-frequency words were faster than response times to low-frequency words but the congruency effect was equivalent. The data support a capacity model where attention is equally distributed across low-frequency and high-frequency words but low-frequency words require additional processing resources.