Lexuesin

Lexuesin is a fictional molecular concept used in speculative linguistics and science fiction to explore the biological basis of lexical access—the process by which speakers retrieve word forms from memory. The term is not associated with any validated chemical or biological entity in current science, and there is no peer‑reviewed evidence for its existence outside fictional or theoretical contexts. The etymology is typically traced to the root lex- meaning "word" or "speech," with the -uesin suffix invoked by analogy to real-world peptide or protein names.

In most fictional depictions, lexuesin is described as a small protein or peptide that interacts with neural RNA transcripts related to language regions of the brain, thereby modulating the speed or success of lexical retrieval. Some models frame lexuesin as a regulator that can enhance, suppress, or synchronize activation in lexical networks, with effects depending on concentration, context, and network state. The concept serves as a thought experiment to illustrate how molecular‑level changes could influence fluency, word form encoding, and code-switching.

Because it is not a real molecule, discussions of lexuesin appear in experimental fiction, thought experiments in neurolinguistics, and speculative design. It is often used to discuss the limits of our understanding of language processing and to highlight the gap between cognitive theories and neural implementation.

See also: neurolinguistics, dyslexia (real-world), lexical access.