Are altered states subjective or measurable?
Short Answer
Altered states are both subjective experiences and measurable phenomena, with brain imaging, EEG patterns, heart rate variability, and biochemical markers providing objective correlates of reported consciousness changes.
Why This Matters
Understanding this duality matters because it bridges the gap between first-person experience and third-person science. Subjectively, altered states involve qualitative shifts in how awareness feels—time may slow, colors intensify, or self-boundaries dissolve. These subjective reports can be correlated with objective measurements: theta brainwaves during deep meditation, reduced default mode network activity during psychedelic states, or elevated cortisol during acute stress states. This correlation doesn't reduce the experience to brain activity but demonstrates that consciousness changes leave measurable signatures, allowing researchers to study states that were once considered purely mystical or unmeasurable.
Where This Changes
The correlation weakens for subtle states where physiological changes are minimal or for unique experiences that don't map onto existing measurement frameworks. Two people can show identical EEG signatures yet report vastly different subjective experiences, demonstrating that objective measures capture correlates but not the full phenomenology of consciousness.