Abstract Grammar in Broca’s Area – Noun & Verb Inflection

The brain basis of abstract grammar, the feat that allows language to express infinite thoughts with a finite menu of words, has been notoriously difficult to identify because many other faculties vary with grammatical complexity. For instance, sentences that have greater grammatical complexity usually also demand more working memory, integration costs, selection demands, etc. Therefore it is hard to compare grammatically complex sentences to grammatically simple ones, as a way to isolate grammatical processing in brain activity.

Meanwhile, discovering the core function of Broca’s area, arguably the most widely known brain center, has defied 150 years of research: in part due to tasks that varied multiple faculties, but also in part due to methods with low temporal or spatial resolution (like fMRI or MEG).

This paper uses grammatical inflection as a model system for grammar that sidesteps many confounds (see the task description and discussion in the paper), and event-related fMRI to identify the neural territories involved. The goal was to identify the full extent of these neural territories with fMRI, and then investigate computations within them in further temporal and physiological detail, using the ICE method (see other Results pages).

We asked whether Broca’s area computes grammar per se, what regions are responsible for inflecting vs. pronouncing words, and if nouns and verbs are inflected by the same neural processors or separate ones. The paper that reports the results is here in PDF form.

This paper introduced the language task I have used in several other studies, and which began several threads of continuing research. These research lines include: neural processing of grammar, noun-verb differences, the nature of Broca’s area, and the components of neurolinguistic processing underlying production. Also, the paper may be useful in the classroom, because it includes a review-length introduction as well as discussion section, which provide literature review and technical background material that may suit a psycholinguistics or fMRI-methods course. I hope you will download the paper and use it!

BTW, For list of papers that cite this one (30), click: here.       (Note: this list is old and is missing about 10 citations. Coming soon.)