Search Abstracts | Symposia | Slide Sessions | Poster Sessions
Meaning Beyond Experience: Neural Evidence for Grammar-Based Semantic Generalization
Poster Session A, Wednesday, September 30, 11:00 am - 1:00 pm, Wangari Maathai
Marianne Azar1, Alec Marantz1; 1New York University
INTRODUCTION A central heuristic of cognition is the ability to generalize beyond direct experience. From previous encounters, we infer what to expect from future instances, what contexts they might appear in, and how to interpret them. Most importantly, we can learn and generalize even when the relationship between instances and their contexts are probabilistic rather than certain. This ability is especially central to language learning, where grammatical form (ery in bakery; brewery) often supports expectations about meaning (places). Across languages, although grammar-meaning relations are reliable, they are not certain (cookery; savagery!). However, this does not seem to hinder our ability to generalize. In this study, we asked how in the brain such a grammar–meaning relation emerges over the course of learning and is subsequently applied. First, how do phonological, morphological, and semantic processing change as a process of word-learning and consolidating a grammar-meaning relationship among words? Second, if words are processed abstractly, how will processing of majority/minority words of the same form differ? Third, how does the neural signature of semantic generalization compare to that of semantic comprehension? METHODS Using MEG and an English-embedded artificial grammar learning paradigm, 28 participants learned and were tested on the meanings of novel complex words (“drinkle”) from context (“This drinkle closes on Mondays”). In the test phase, similar sentences they judged as sensical/not had either trained words or untrained ones needing generalization ("We went to the thinkle by foot" MADE SENSE?). Learners were naive to this distinction. Across items, two suffixes carried opposing 75:25 majority/minority meaning distributions of places and objects. This design allowed us to track the emergence of the suffix–meaning relation, its generalization to novel items, and the integration of majority/minority meaning within the emerging semantic system. RESULTS. FROM FORM TO MEANING: As the experiment progressed, processing shifted, attenuating orthographo-phonological processing indicated by decreasing precentral cortex activity (100-176 ms) (Liuetal.,NatureHuman Behaviour2025), and amplifying semantic processing indicated by increasing Superior Temporal Gyrus activity (100-215 ms) (Friedericietal.,CerebCortex2003). ABSTRACTION AND SENSITIVITY TO MEANING DISTRIBUTIONS Despite individual words being as frequent, in under an hour, learners were sensitive to a difference between majority- and minority-meaning words, especially the most frequent ones. This was associated with increased activity for minority-meaning words in the pars opercularis (321-475 ms), associated with semantic-driven syntactic processing (Zhangetal.,NeuroImage2024). This suggests learners can rapidly move beyond item-level word meanings to abstract a two-pronged suffix-level semantic regularity. SHARED SUBSTRATE BETWEEN TRAINED COMPREHENSION AND GENERALIZATION Representational similarity analysis revealed that, early in learning, trained words and those requiring generalization were distinguishable in the temporal pole associated with semantic integration, (Pattersonetal.,NatRevsNeuro2007). By the final third, activity for trained and generalized items converged, suggesting that learning supports the integration of both familiar comprehension and novel generalization into the same representational space. CONCLUSION Overall, these findings show learners rapidly build abstract grammar–meaning relations from contextual word learning, even with uncertainty, while nevertheless representing that uncertainty. We found that semantic generalization is possible as soon as a grammar-meaning relation is integrated, and is in fact, indistinguishable from comprehension.
Topic Areas: Meaning: Lexical Semantics, Morphology