Marianne Gullberg is Professor of Psycholinguistics and Director of the Humanities Lab at Lund University, Sweden. With Peter Indefrey she previously headed the research project "The Dynamics of Multilingual Processing" at the Max Planck Institute for Psycholinguistics, Nijmegen. Her research focuses on the earliest stages of adult second language acquisition and on the advanced or bilingual stage, examining lexical semantics, cross-linguistic (bi-directional) influences, code-switching, and the production and comprehension of gestures. She has published in a range of journals, including Language Learning, Studies in Second Language Acquisition, Bilingualism: Language and Cognition, and Brain and Language.

Peter Indefrey is Professor of Psycholinguistics and Neurolinguistics at the Heinrich Heine University Düsseldorf, Germany, and research fellow at the Donders Centre for Cognitive Neuroimaging in Nijmegen. With Marianne Gullberg he previously headed the research project "The Dynamics of Multilingual Processing" at the Max Planck Institute for Psycholinguistics. His research is on first and second language processing and their neural correlates. Some of his favorite topics are syntactic and morphological processing, word production, reading, and the development of language processing in L2 learners. He has published in a variety of journals, including Cognition, PNAS, Neuroimage, Journal of Experimental Psychology, and Journal of Cognitive Neuroscience.