What’s so great about Glastonbury? As I’ve never been, I often wonder. Clearly the music and suspension of social norms that makes rolling in the mud seem like a good idea can encourage a new mindset.Some of the 175,000-strong crowd famously reach this altered state through psychoactive substances. However, the change to neural activity caused by psychedelic drugs isn’t as significant as you might think.
Whatever a stoned hippy might tell you in a field at 3am, hallucination isn’t an entirely different way of seeing - it’s just a different balance between what you’re imagining and what’s going into your eyes. Even when you’re sober, what you see is driven by expectations and prejudices, what you’ve seen in the past and what you’re thinking about at that moment. We constantly see shapes that look like objects and things that aren’t really there – but you are more likely to do a double-take and look more closely at whatever is in front of you if you’re not high. Hallucinogens can pause this inner fact-checking mechanism and cause us to project our memories and musings out into the real world – hence the purple clouds and talking teacups.
Dr Daniel Glaser is director of Science Gallery at King’s College London
