An in-depth conversation with Ellen Bialystok, Professor of Psychology at York University, who is a world-leading expert on the effects of bilingualism on cognitive processes across our lifespan.

Five scientists (Carol Padden, Victor Ferreira, Martin Monti, Ellen Bialystok, Greg Hickok) explore the question of what language is, from investigations on bilingualism and its relation with neuroplasticity to what it means to have an impairment when using sign language.