How sleeping minds decide: State-specific reconfigurations of lexical decision-making.
PLoS Computational Biology February 1, 2026 Tao Xia, Chuan-Peng Hu, Başak Türker et al.
Sleep is often seen as a state of mental disconnection, but new research shows that decision-making abilities can persist during certain sleep stages. Using facial muscle measurements and computational modeling, the study found that people could make lexical decisions (distinguishing real words from pseudowords) during N1 sleep and lucid REM sleep, though through different brain processes. During N1 sleep, both enhanced sensory-motor processing and increased evidence accumulation supported decisions about words, while pseudowords were selectively impaired, suggesting cognitive resources prioritize meaningful stimuli. In lucid REM sleep, decisions relied solely on evidence accumulation, and participants raised their decision thresholds, requiring more evidence before responding to maintain accuracy despite reduced efficiency. Sleep involves dynamic, state-specific reconfiguration of decision-making mechanisms rather than passive cognitive decline.