Areas that contributed to vision were much more active when under the influence of LSD Imperial College London / Beckley Foundation

This is what the human brain looks like when it is under the influence of LSD, researchers at Imperial College London have revealed.

In a study, published in Proceedings of the National Academy of Sciences (PNAS), the medical scientists revealed what happens in the brain when people have LSD-induced hallucinations. Scans showed volunteers' brains lighting up with activity after taking LSD; usually only the visual cortex at the rear of the brain is involved with image processing.


Dr Robin Carhart-Harris who led the research suggested that the volunteers were "seeing with their eyes shut" while hallucinating on LSD. "We saw that many more areas of the brain than normal were contributing to visual processing under LSD – even though the volunteers' eyes were closed. Furthermore, the size of this effect correlated with volunteers' ratings of complex, dreamlike visions."

The researchers, working in collaboration with the Beckley Foundation, also explored how LSD alters the experience of consciousness. Carhart-Harris, from Imperial, said that the brain on LSD becomes more "integrated or unified" as the separateness between different brain functions (i.e. vision, movement, hearing) starts to dissolve. "Our brains become more constrained and compartmentalised as we develop from infancy into adulthood, and we may become more focused and rigid in our thinking as we mature," Carhart-Harris said. In many ways, the brain in the LSD state resembles the state our brains were in when we were infants: free and unconstrained. This also makes sense when we consider the hyper-emotional and imaginative nature of an infant's mind."

A brain under placebo (left) compared to a brain under the influence of LSD (right) Imperial College London / Beckley Foundation

Twenty healthy volunteers were injected with either LSD or a placebo and had their brains scanned by fMRIs and other imaging technology to study the impact of the drug. Researchers used these imaging techniques to monitor blood flow and electrical activity as a way of 'seeing' when distinct areas of the brain were active. "This is to neuroscience what the Higgs boson was to particle physics," study author David Nutt told The Guardian. Nutt was previously the government's chief drug advisor before being asked to resign in 2009 after he claimed that ecstasy and LSD were less dangerous than alcohol.


This current research project is one of only a handful of studies to be conducted on the effects of LSD on the human brain. In 2014, researchers in Switzerland became the first scientists to give volunteers LSD in 40 years.

Researchers from the Beckley/Imperial Research Programme also looked into the the effect that listening to music while on LSD had on the brain. They found that the combination of LSD and music altered visual cortex activity in the brain and caused the visual cortex to receive more information associated with mental imagery and personal memory.

Amanda Fielding, Director of the Beckley Foundation said: "We are finally unveiling the brain mechanisms underlying the potential of LSD, not only to heal, but also to deepen our understanding of consciousness itself."