No tiger in plastic tiger: Local linguistic context alters the neural representations of individual words
In the authors' words
Language is vastly ambiguous, yet in context our brains resolve ambiguity effortlessly. This is particularly evident at the lexical level: Although most words can convey a wide range of related meanings, humans rapidly and automatically select the one appropriate for the context. We investigated the neural mechanisms underlying this process by focusing on a case where, intuitively, one meaning appears more basic than another: nouns describing animate entities, such as tiger, which can also refer to representations of those entities when combined with a material modifier, as in plastic tiger. Using magnetoencephalography, we decoded animacy from neural signals and found that even in such cases, our approach revealed no evidence that the tiger in plastic tiger is represented as a sentient animal in any stage of processing. Instead, phrase-level animacy--plastic tiger as inanimate--was decodable as early as 210 ms post-stimulus onset and persisted for several hundred milliseconds. These findings challenge theories assuming a shift from a basic sense of a word to a more derived one, highlighting instead the role of compositional context in shaping word meanings.
Appeared: Friday, September 25. bioRxiv. Preprint, not yet peer-reviewed.