Factives at hand: When presupposition mode affects motor response.

It is well established that the processing of hand-, mouth-, and foot-related action terms can activate areas of the motor cortex that are involved in the planning and execution of the described actions. In the present study, the sensitivity of these motor structures to language processes was exploited to test linguistic theories on information layering. Human languages possess a variety of linguistic devices, so-called presupposition triggers, that allow us to convey background information without asserting it. A statement such as "Marie stopped smoking" presupposes, without asserting it, that Marie used to smoke. How such presupposed information is represented in the brain is not yet understood. Using a grip-force sensor that allows capturing motor brain activity during language processing, we investigated effects of information layering by comparing asserted information that is known to trigger motor activity ("In the living room, Peter irons his shirt") with information embedded under a presuppositional factive verb construction ("Louis knows that Peter irons his shirt"; Experiment 1) and a nonfactive verb construction ("Louis believes that Peter irons his shirt"; Experiment 2). Furthermore, we examined whether the projection behavior of a factive verb construction modulates grip force under negation ("Louis does not know that Peter irons his shirt"; Experiment 3). The data show that only the presupposed action verb in affirmative contexts (Experiment 1) triggers an increase in grip force comparable to the one of asserted action verbs, whereas the nonfactive complement and projection structure show a weaker response (Experiments 2 and 3). While the first two experiments seem to confirm the sensitivity of the grip-force response to the construction of a plausible situation or event model, in which the motor action is represented as taking place, the third one raises the question of how robust this hypothesis is and how it can take the specificity of projection into account. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

[Stahl, Leibniz, Hoffmann and breathing]. / Stahl, Leibniz, Hoffmann et la respiration.

At the beginning of the XVIII th century, Wilhelm Gottfried Leibniz and Friedrich Hoffmann criticize Georg Ernst Stahl's medical theory. They differenciate between unsound and true reasonings. Namely, they validate Stahl's definition of breath but extracting it from its animist basis and placing it in an epistemology obeying to the principle of sufficient reason and to the mechanical model. The stahlian discovery consists in understanding breath as a calorific ventilation against the ancient conception; the iatromechanists recognize its accuracy, but they try then to transpose it to a mechanical model of ventilation. Using it in a different epistemological context implies that they analyze the idea of discovery "true" in its contents, but "wrong" in its hypothesis. It impels to examine the epistemology of medical knowledge, as science and therapeutics, and in its links with the other scientific theories. Thus, if Leibniz as philosopher and Hoffmann as doctor consider Stahl's animism so important, it is because its discoveries question the fundamental principles of medicine.