A shared neural substrate for action verbs and observed actions in human posterior parietal cortex
High-level sensory and motor cortical areas are activated when processing the meaning of language, but it is unknown whether, and how, words share a neural substrate with corresponding sensorimotor representations. We recorded from single neurons in human posterior parietal cortex (PPC) while participants viewed action verbs and corresponding action videos from multiple views. We find that PPC neurons exhibit a common neural substrate for action verbs and observed actions. Further, videos were encoded with mixtures of invariant and idiosyncratic responses across views. Action verbs elicited selective responses from a fraction of these invariant and idiosyncratic neurons, without preference, thus associating with a statistical sampling of the diverse sensory representations related to the corresponding action concept. Controls indicated that the results are not the product of visual imagery or arbitrary learned associations. Our results suggest that language may activate the consolidated visual experience of the reader.
© 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). Submitted 25 February 2020; Accepted 3 September 2020; Published 23 October 2020. We would like to thank N.S. and E.G.S. for participating in the studies, V. Scherbatyuk for technical assistance, and K. Pejsa for administrative and regulatory assistance. We would also like to thank M. Rugg for helpful comments on an early version of this manuscript. This work was supported by the NIH (R01EY015545), the Tianqiao and Chrissy Chen Brain-machine Interface Center at Caltech, the Conte Center for Social Decision Making at Caltech (P50MH094258), the Boswell Foundation, and ERC (Parietal action) VII FP (323606). Author contributions: Conceptualization: T.A. Methodology: T.A. and G.A.O. Investigation: T.A. and C.Y.Z. Formal analysis: T.A. Writing (original draft): T.A. Writing (review and editing): T.A., G.A.O., and R.A.A. Funding acquisition: T.A., G.A.O., and R.A.A. Resources: E.R.R. and N.P. Supervision: T.A., G.A.O., and R.A.A. The authors declare that they have no competing interests. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors.
Submitted - 2020.04.20.039529v1.full.pdf
Supplemental Material - abb3984_SM.pdf
Published - eabb3984.full.pdf