Consciousness research
Consciousness research investigates subjective experience and its relationship to the brain, body and environment. It brings together neuroscience, psychology and philosophy.
What is consciousness?
Consciousness is what makes life feel like something from the inside: seeing a colour, feeling joy or noticing a thought. It is familiar to all of us, yet how brain activity relates to personal experience remains a major puzzle.
Researchers study wakefulness, sleep, anaesthesia, attention and the brain processes linked to awareness. They also test different theories of how conscious experience arises.
What does research say?
Using methods such as EEG, which measures the brain’s electrical activity, and functional magnetic resonance imaging (fMRI), which shows changes in blood flow in the brain, researchers can investigate patterns of brain activity associated with conscious experiences. For example, researchers compare moments when a person notices an image with moments when the same image goes unnoticed.
Different theories make different predictions, and recent experiments have tested some of them head-to-head. No single theory has fully explained consciousness. Finding a brain correlate is not the same as explaining why experience feels like anything at all.
One way to study awareness is to show an image so briefly that a person sometimes notices it and sometimes does not. Researchers compare brain activity in those moments. They also study what changes when people fall asleep, receive anaesthesia or wake up.
Different theories focus on different aspects of brain processing. Some emphasise information being shared across networks; others focus on how information is integrated. Each theory makes predictions that experiments can test.
A major challenge is separating the experience itself from the act of reporting it. Pressing a button when you see an image involves both awareness and a response. Researchers therefore also design tasks that require less direct reporting.
One question is the difference between being awake and being aware. Someone may have open eyes without experiencing the surroundings in the usual way. Meanwhile, a dreaming person can have vivid experiences while asleep. These contrasts help researchers identify what matters for awareness.
Researchers may present the same faint image or sound several times. Sometimes a person notices it and sometimes not. Comparing brain activity across those moments can reveal useful clues without trying to solve every philosophical question at once.
Brain measurements are not always straightforward to interpret. A pattern seen during an experience might help create it, make it possible or happen afterwards. Carefully designed experiments are needed to tell these possibilities apart.
A theory that some researchers are exploring is that consciousness may be non-local (non-local consciousness), meaning that it might not be entirely confined to the brain. This could mean that consciousness is not solely produced by the brain but might also exist independently of it. Some researchers are investigating whether experiences such as telepathy and near-death experiences can offer clues about how consciousness works. A 2024 research review compared several theories of non-local consciousness and considered how they could be tested scientifically. The researchers argued that these theories deserve further investigation, but that clearer tests and stronger evidence are needed. So far, there is no convincing scientific evidence that consciousness can exist independently of the brain.
What do the findings show?
There are strong links between brain states and what people experience. Researchers can measure many of these links and test competing ideas. Brain measurements can often track changes in wakefulness and perception, which is a major scientific achievement.
What remains uncertain?
Personal experience cannot be measured directly like pulse or temperature. Scientists combine reports, behaviour and brain measurements, each with limits. Explaining some experiments is not the same as explaining all experience. Different measurements capture different aspects of brain activity.
Overall assessment
Much is known about brain processes associated with awareness, but how and why subjective experience arises remains debated. Progress comes from testing clear predictions, but why brain activity feels like something from the inside remains an open question.