The ability to comprehend and produce language stands as a defining characteristic of human cognition. Language scientists have made great strides in understanding the functional and neural mechanisms underlying the use of spoken language, however, equivalent knowledge in the domain of signed languages is lacking. The long-term objective of my research is to develop a comprehensive neurocognitive model of sign language processing derived from behavioral and functional brain-imaging studies. In this talk I will present data from psycholinguistic and neurolinguistic studies of American Sign Language and discuss implications for functional-anatomical models of human language processing.