ABSTRACT
In a letter detection experiment in which asterisks or blank spaces were inserted between characters in continuous text, participants made significantly fewer errors when the test word subtended a larger visual angle. In a second experiment, the interword space before the test word the was found to be more critical for unit formation than the space after the. These results suggest that the size of the processing units used by readers depends on visual angle and that the reading units for frequent function words such as the extend beyond the word itself, include the interword space, and are influenced more by familiarity than by linguistic function. These findings are discussed in terms of the notions of cognitive module and input system proposed by Fodor (1983).
