After recalling the theoretical issues involved in the study of human singularity, the first lecture focused on the cerebral networks of language. Are these networks really specific to the human species ? A brief review of comparative functional anatomy (to be developed in the 2017-2018 lecture entitled " Origins of language and singularity of the human species ") suggests that the inferior frontal region, and its connections with the temporal and inferior parietal areas via the arcuate fasciculus, have undergone a particular expansion in the human species. Functional MRI suggests that Broca's area may have a particular function in the human primate, that of gathering information in the form of arborescent or embedded representations.
The lecture focused in particular on recent laboratory data showing how these language areas code for sentence structure. This research, carried out by Matt Nelson, Imen El Karoui and several other members of the laboratory and the fruit of over five years' work, involved analyzing intracranial recordings from twelve epilepsy patients as they read sentences in English or French. The neurophysiological responses validated a key hypothesis of contemporary linguistic theories : the existence of a representation of sentences in the form of embedded syntagms. Signals in the gamma frequency band increase with successive words, but suddenly decrease at the boundary of a phrase. The analysis showed the superiority of the syntagmatic model over other models based solely on statistical learning of transition probabilities between words or word categories, in most language areas of the left hemisphere. In addition, we have shown that it is possible to determine which of several parsers proposed by linguists best match the responses of the human brain. The results reinforce Hauser, Chomsky and Fitch's hypothesis that the core of the language faculty consists in the ability to represent word sequences in the form of recursively embedded syntactic trees.
