Consciousness: Quantum experiments add weight to a fringe theory

Experiments on how anaesthetics alter the behaviour of tiny structures found in brain cells bolster the controversial idea that quantum effects in the brain might explain consciousness

By Thomas Lewton

The controversial idea that quantum effects in the brain can explain consciousness has passed a key test. Experiments show that anaesthetic drugs reduce how long tiny structures found in brain cells can sustain suspected quantum excitations. As anaesthetic switches consciousness on and off, the results may implicate these structures, called microtubules, as a nexus of our conscious experience.

According to some interpretations of quantum mechanics, a system can exist in multiple states simultaneously …