Broca's biases in modern aphasiology

Broca's description of aphemia signals the emergence of aphasiology as a discipline. It also marks the beginning of a long tradition of studies of right-handed patients ("Nous parlons avec l'hémisphère gauche") with lesions in the inferior frontal gyrus (Broca's area) displaying production deficits (Broca's aphasia) in their single, mainly Romance or, as years went by, Germanic language. In modern-day aphasiology, language crosses hemispheric boundaries, production is no longer confined to the left inferior frontal gyrus, and lesions in Broca's area do not necessarily entail Broca's aphasia, with recognized production deficits associated with other lesion locations and aphasia types. Nonetheless, idealized monolingual speakers are still at the center of most theories and shape the design of clinical materials. In this paper, we address two key questions Broca left unanswered: (1) How well do current linguistic theories accommodate the diversity of typologies in the nearly 7,000 languages of the world? and (2) How adequate are our clinical resources for the assessment and treatment needs of multilingual individuals? After an introduction, we will discuss crosslinguistic contributions to the development of modern aphasiology in section 2. Section 3 will focus on multilingual aphasia studies.