Grades 9–12 · Organisms
How can scientists study a conscious experience they cannot directly share?
Seeing a color has a subjective side: what the experience is like for the person seeing it. Scientists cannot directly observe another person’s experience as if it were a photograph. They can compare descriptions and behavior with measurements of brain activity.
In the diagramReports and neural measurements are distinct evidencecontrolled imageparticipant reportbrain measurementcompare predictionsNeither stream alone is a direct readout or a finished theory of consciousness.
In an experiment, researchers can present controlled images and record what participants report seeing. Measurements such as electrical recordings or magnetic resonance signals reveal different aspects of neural activity. Their timing, spatial detail and indirectness differ, so they are not interchangeable windows into the mind.
An activity pattern associated with a report may reflect the experience, attention, a decision or preparation to answer. Experiments therefore need comparisons that separate these possibilities. Competing theories can specify different predictions before the results are collected, making disagreement more testable.
A large 2025 collaboration tested predictions from two prominent theories and challenged important parts of both. This was progress in evaluating explanations, not a final solution. How subjective experience arises remains unsettled; naming a brain region or neurotransmitter does not by itself answer that question.
About this explanation
Starting knowledge: Understand neurons, brain activity measurements and the distinction between a correlation and a causal explanation.
Sources
- Cogitate Consortium and colleagues, Nature — Adversarial testing of global neuronal workspace and integrated information theories of consciousness