Bilinguals are able to compose expressions across their languages with seeming ease. This phenomenon, commonly referred to as "code-switching," has challenged both theoretical models in linguistics as well as neurobiological models of language processing. And yet, our models of the bilingual brain and the language processing mechanism remain largely siloed from each other. In this dissertation, I present three studies that begin to bridge knowledge gained from each body of research in order to develop a model of bilingual language processing. The first study demonstrates how combinatory mechanisms housed in regions implicated for composition behave indifferently to mixed-language input as compared to single-language input. The second study provides preliminary evidence to suggest that switching languages does not disrupt gender agreement, a linguistic phenomenon known to facilitate early stages of processing. And the third study provides support for alternative syntactic constructs that guide how bilinguals build mixed-language structural representations. Taken together, these studies shed new light on the language processing mechanism housed within the bilingual brain. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]