CONICET | Buscador de Institutos y Recursos Humanos

Word meaning seems to depend on fast reactivations of sensorimotor circuits engaged by relevant extralinguistic experiences. Despite abundant compatible evidence, this view has been criticized because most reported effects lack fine-grained neuroanatomical precision and are not rapid enough to rule out post-comprehension (e.g., imagery) effects. Here we profited from the excellent spatio-temporal resolution of intracranial recordings to assess whether face-related words yielded early resonance in the highly specialized fusiform face area (FFA). Participants performed a semantic decision task on words denoting facial body parts, non-facial body parts, and familiar objects. We defined two regions of interest (ROIs), one comprising key FFA hubs and one including temporal areas implicated in amodal semantics. Time-frequency charts for each word type were obtained from digitized signals via a windowed Fourier transform. Also, logistic regression analyses were performed to evaluate whether power activity across each trial predicted stimulus type. Relative to names of non-facial body parts and objects, words denoting facial body parts yielded significant activation increases in both ROIs at low frequencies (0-20 Hz). This effect was stronger and earlier in the FFA (125-250 ms) than in the temporal (175-400 ms) ROI. Moreover, logistic regressions based on such patterns classified each word type with over 70% accuracy. Our findings show that face-related words trigger very rapid embodiment effects within neural hubs specialized for face perception. The time course of activity across ROIs further indicates that word comprehension first engages embodied mechanisms and then leads to further operations in more general (arguably amodal) semantic networks.