Beyond Broca and Wernicke

Abstract: Broca and Wernicke are dead, or moving past the classic model of language neurobiology

With the advancement of cognitive neuroscience and neuropsychological research, the field of language neurobiology is at a cross-roads with respect to its framing theories. The central thesis of this article is that the major historical framing model, the Classic “Wernicke-Lichtheim-Geschwind” model, and associated terminology, is no longer adequate for contemporary investigations into the neurobiology of language. We argue that the Classic model (1) is based on an outdated brain anatomy; (2) does not adequately represent the distributed connectivity relevant for language, (3) offers a modular and “language centric” perspective, and (4) focuses on cortical structures, for the most part leaving out subcortical regions and relevant connections. To make our case, we discuss the issue of anatomical specificity with a focus on the contemporary usage of the terms “Broca’s and Wernicke’s area”, including results of a survey that was conducted within the language neurobiology community. We demonstrate that there is no consistent anatomical definition of “Broca’s and Wernicke’s Areas”, and propose to replace these terms with more precise anatomical definitions. We illustrate the distributed nature of the language connectome, which extends far beyond the single-pathway notion of arcuate fasciculus connectivity established in Geschwind’s version of the Classic Model. By illustrating the definitional confusion surrounding “Broca’s and Wernicke’s areas”, and by illustrating the difficulty integrating the emerging literature on perisylvian white matter connectivity into this model, we hope to expose the limits of the model, argue for its obsolescence, and suggest a path forward in defining a replacement.

“Broca and Wernicke are dead, or moving past the classic model of language neurobiology” by Pascale Tremblay and Anthony Steven Dick in Brain and Language. Published online August 30 2016 doi:10.1016/j.bandl.2016.08.004

You can find the paper here (behind a paywall):

http://www.sciencedirect.com/science/article/pii/S0093934X16300475

There's a news article here:

http://neurosciencenews.com/broca-and-wernicke-are-dead-its-time-to-rewrite-the-neurobiology-of-language/

From that article: Tremblay and Dick call for a “clean break” from the Classic Model and a new approach that rejects the “language centric” perspective of the past (that saw the language system as highly specialised and clearly defined), and that embraces a more distributed perspective that recognises how much of language function is overlaid on cognitive systems that originally evolved for other purposes.