The brain on LSD revealed: First scans show how the drug affects the brain
$this->bbcode_second_pass_quote('', 'R')esearchers from Imperial College London, working with the Beckley Foundation, have for the first time visualised the effects of LSD on the human brain. In a series of experiments, scientists have gained a glimpse into how the psychedelic compound affects brain activity. The team administered LSD (Lysergic acid diethylamide) to 20 healthy volunteers in a specialist research centre and used various leading-edge and complementary brain scanning techniques to visualise how LSD alters the way the brain works.
The findings, published in Proceedings of the National Academy of Sciences (PNAS), reveal what happens in the brain when people experience the complex visual hallucinations that are often associated with LSD state.
A major finding of the research is the discovery of what happens in the brain when people experience complex dreamlike hallucinations under LSD. Under normal conditions, information from our eyes is processed in a part of the brain at the back of the head called the visual cortex. However, when the volunteers took LSD, many additional brain areas - not just the visual cortex - contributed to visual processing.
Dr Robin Carhart-Harris, from the Department of Medicine at Imperial, who led the research, explained: "We observed brain changes under LSD that suggested our volunteers were 'seeing with their eyes shut' - albeit they were seeing things from their imagination rather than from the outside world. 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 study also revealed what happens in the brain when people report a fundamental change in the quality of their consciousness under LSD.
Dr Carhart-Harris explained: "Normally our brain consists of independent networks that perform separate specialised functions, such as vision, movement and hearing - as well as more complex things like attention. However, under LSD the separateness of these networks breaks down and instead you see a more integrated or unified brain.
"Our results suggest that this effect underlies the profound altered state of consciousness that people often describe during an LSD experience. It is also related to what people sometimes call 'ego-dissolution', which means the normal sense of self is broken down and replaced by a sense of reconnection with themselves, others and the natural world.
In addition to these findings, research from the same group, part of the Beckley/Imperial Research Programme, revealed that listening to music while taking LSD triggered interesting changes in brain signalling that were associated with eyes-closed visions.
In a study published in the journal European Neuro-psychopharmacology, the researchers found altered visual cortex activity under the drug, and that the combination of LSD and music caused this region to receive more information from an area of the brain called the parahippocampus. The parahippocampus is involved in mental imagery and personal memory, and the more it communicated with the visual cortex, the more people reported experiencing complex visions, such as seeing scenes from their lives.
Dr Carhart-Harris added: "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.
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."
http://m.pnas.org/content/early/2016/04/05/1518377113


