Sleuthing subjectivity: a review of covert measures of consciousness.
Nature reviews. Neuroscience May 23, 2025 Sharif I Kronemer, Peter A Bandettini, Javier Gonzalez-Castillo 5 citations
Consciousness is inherently private, but overt behaviors like facial expressions and vocalizations are unreliable indicators because they can be deceptive, absent, or conflict with research goals. This review examines emerging covert physiological measures—including eye, skin, respiratory, and heart signals—that can disclose consciousness without relying on overt behavior. It also addresses the challenge of distinguishing physiological signals linked to conscious versus unconscious neural processing and considers the ethical implications of infringing on the innate privacy of consciousness.