Neighbourhood effects on masked form priming in developing readers

The processing of a written word can be facilitated by the brief prior pres entation of an orthographically similar stimulus, However, for adults, this masked form-priming effect does not occur if the target looks like many ot her words (i.e. if it has many neighbours). The usual interpretation of thi s result is that the adult word recognition system is tuned to the differin g discrimination demands of words: If a word looks like many others, a more precise recognition procedure is required than if it is orthographically d istinctive. This theory has developmental implications: Children should sho w more form priming for high neighbourhood words than adults and should sho w a gradual reduction in priming as their written vocabularies become large r. Masked form priming was examined in three groups of developing readers, from grades 2, 4 and 6, and a group of adults. In a lexical decision task, the children showed significantly greater priming overall than the adults f or high N words. However, the predicted gradual attenuation across age was not found. Supplementary analyses suggested that the adaptation to lexical density may not occur until a somewhat more advanced stage of reading than we had first expected.