Introspective psychophysics for the study of subjective experience

Studying subjective experience is hard. We believe that pain is not identical to nociception, nor pleasure a computational reward signal, nor fear the activation of ‘threat circuitry’. Unfortunately, introspective self-reports offer our best bet for accessing subjective experience, but many still believe that introspection is “unreliable” and “unverifiable”. But which of introspection’s faults do we find most damning? Is it that introspection provides imperfect access to brain processes (e.g., perception, memory)? That subjective experience is not objectively verifiable? That it’s hard to isolate from non-subjective processing capacity? Here I argue none of these prevents us from building a meaningful, impactful psychophysical research program that treats subjective experience as a valid empirical target through precisely characterizing relationships among environmental variables, brain processes and behavior, and self-reported phenomenology. Following recent similar calls by Peters (2022), Kammerer and Frankish (2023), and Fleming (2023), “introspective psychophysics” thus treats introspection’s apparent faults as features, not bugs – just as the noise and distortions linking environment to behavior inspired Fechner’s psychophysics over 150 years ago. This next generation of psychophysics will establish a powerful tool for building and testing precise explanatory models of phenomenology across many dimensions – urgency, emotion, clarity, vividness, confidence, and more.