It is now well established that phonological -- and orthographic -- codes play a crucial role in the recognition of isolated words and in understanding the sequences of words that comprise a sentence. However, words and sentences are organized with respect to morphological as well as phonological components. It is thus unfortunate that the morpheme has received relatively little attention in the experimental literature, either from psychologists or linguists. Due to recent methodological developments, however, now is an opportune time to address morphological issues.

In the experimental...