Dr. Coughlin's research program uses psycholinguistic and neurolinguistic techniques to investigate how adult second language learners and heritage speakers store and access words in their mental lexicon. More specifically, her research tests hypotheses regarding whether these populations have available to them the mechanisms that allow for access to a morphological level of representation in the lexicon instead of relying on whole-word storage. In addition to testing these hypotheses, Dr. Coughlin incorporates individual difference measures to examine whether differences in reading and spelling ability, as well as proficiency, influence the availability of a morphological level of representation in the mental lexicon.