If a researcher conducted a study to examine people's subjective conscious experiences while taking drugs, they would be most likely to use which methodology?

Answer 1

Studies of this nature have been performed using various substances. They are always mixed methods - using quantitative analysis for the measurement and distribution of the substance and qualitative anaylysis (such as self-reporting, interviews, and questionnaires) for the subjective experience. For a great example of a mixed methods study on Psilocybin and Consciousness, see Kometer et al., (2015).

Kometer, M., Pokorny, T., Seifritz, E., & Volleinweider, F. X. (2015). Psilocybin-induced spiritual experiences and insightfulness are associated with synchronization of neuronal oscillations. Psychopharmacology, 232(19), 3663-3676. https://doi.org/10.1007/s00213-015-4026-7

Answer 2

Because the goal is to examine the SUBJECTIVE conscious, the best methodology to use would be self-reporting measures such as a survey or free response. Any test or measure that is reliant on someone's own report of their individual beliefs, attitude, symptoms, etc. would be best to use.