Language is a fundamental human cognitive ability. It plays an important role in normal development and is the major means for acquiring information in many domains. A number of psychological disorders, including autism, can disrupt the normal functioning of this system. This study investigates spoken language processing and how presentation of a spoken word leads to a mental representation of that word, also referred to as a lexical representation. The proposed experiments will track how lexical representations of particular words shift across time, across number of exposures to the words, and across the phonetic details of the words. The product of the proposed research will be a much better understanding of the architecture of the system that accomplishes language comprehension. Because language is such a fundamental cognitive ability, progress in describing language processing will enhance our understanding of human cognition under both normal and disordered conditions.