Book: How to Change Your Mind by Michael Pollan Art: Indian Hunter at Sunset by Henry Raschen Reading time: 6 mins
When neuroscientist Dr Robin Carhartt-Harris and his team wanted to study how Psilocybin mushrooms, a type of psychoactive fungi, interact with the brain, his initial hypothesis was that the psychedelic experience would increase cerebral blood flow. They predicted that in an fMRI scanner, this would show up as increased oxygen levels across the brain. They noticed, however, that there was a significant decrease in oxygen level concentrated around one specific brain structure, the default mode network.
The default mode network (DMN) was discovered in 2001 by a neurologist named Marcus Raichle. When Raichle was studying volunteers in an fMRI scanner, he noticed that when they were waiting in the scanner to take part in a test, several parts of the brain showed heightened activity. This was the brains ‘default mode’ and this network of structures light up when the brain has no task to perform. In other words, the DMN is where our minds go to daydream, self reflect and worry.
The DMN also plays a key role in creating mental constructs. One of these constructs is what psychologist Sigmund Freud called the ‘ego’, which some neuroscientists call “the me network”. The ego is a mental mechanism that the mind creates to distinguish the ‘I’ as a separate entity from ‘them’ and ‘that’. It is the ego which is concerned with how we are viewed and how we form our identity based on our experiences. This is why the DMN lights up when we get ‘likes’ on social media and when we go back into our autobiographical memory.
Philosopher Aldous Huxley believed that when it comes to our perception of reality, the ego acts asa filter. He stated while we may believe that we view the world in its totality, the ego acts like a ‘reducing valve’ which only perceives the information we need to survive. This is so that we use energy resourcefully and so that our brains do not process everything that is received from the world.
This is also the reason why human consciousness is so different from the consciousness of other animals. For example, while we can see specific colours, bees can perceive electrical signals from plant petals, and they can distinguish between different signals like we do colours. The human brain and bee brain differs in what it’s conscious of and neither is fully conscious of all that is out there. Because of this reducing valve, our everyday awareness is an inhibited version of full awareness.
The evolution of the ego was a great evolutionary step as it allowed humans to focus on the advancement of the self. This is because the ego is only concerned with being conscious of that which is needed for getting ahead, getting food and reproducing. But this mechanism also comes with some drawbacks. As the ego distinguishes our self from others and the world, it separates us from everything external from us, leading to a sense of isolation.
“A human being is part of the whole called the ‘Universe’, a part in time and space. he experiences himself, his thoughts and feeling as something separated from the rest – a kind of optical delusion of his consciousness. This delusion is a kind of prison for us.”Albert Einstein, The Einstein Papers: A Man of Many Parts
Furthermore, if the DMN is faulty it can lead to excessive self-reflecting and worrying, and the ego’s rigid filter will hinder the mind from opening up to more than its current thoughts. This inevitably leads to destructive behaviours. Once consumed, psychedelics dis-inhibit the reducing valve of the ego and quieten the DMN. The psychedelic experience loosens the filter and frees the mind to enter other realms of consciousness. It allows the mind to create new thoughts.
Carhartt-Harris theorised that some psychological disorders were the result of excessive order in the mind and not a lack of order. He suggested that when the DMN settles into the same rigid patterns of thought, the mind is unable to create new mental states and ways of thinking. Research has shown that a hyperactive DMN causes individuals to be trapped in repetitive and destructive loops of self-reflection which eventually shut the person off from the outside world. Disorders such as depression, obsessive-compulsive disorder (OCD) and addiction are characterised by excessively rigid patterns of thought.
Psychedelics have been shown to disrupt these patterns. The exact way they do this is uncertain but research points to their neurochemical effects on the brain. Psychedelic compounds bind to serotonin receptors causing neurons to fire in a certain way. This firing of new signals disrupts the usual oscillations of the DMN. You can imagine this if you think of an audience clapping in the same rhythm. If there a few people who produce some wayward claps, the entire rhythm will desynchronise to chaos.
Once these patterns are disrupted, the mind is then free to create new possibilities. In the picture at the start of the blog is a simplified model of the number of neurological connections in the brain between a non-active placebo (left) and psilocybin (right). As we age, our perception of reality is filtered and our brains become efficient machines in dealing with life’s everyday situations. This causes the neural connections in our brain to act automatically almost by habit and these connections become ingrained. This is what the image on the left is showing. The image on the right shows all the new connections the mind makes when on a psychedelic.
Studies show that this psychedelic experience has profound effects on addiction in particular. In one study, 80% of addicted smokers who were given psilocybin achieved cessation of their habit, a rate that has yet to be achieved by other smoking cessation treatments. Other studies showed that after psychedelic experiences, addicts admitted a sense of awe at being connected to the world and others and because of this, recognised the harm that they were doing. Furthermore, Bill Wilson, who is the founder of Alcoholics Anonymous (AA), implemented in AA the lesson of surrendering to a higher power because of his spiritual experience with a psychedelic drug.
“Psychedelics would be for psychiatry what the microscope is for biology and the telescope is for astronomy.”Dr. Stanislav Grof
While psychedelics, as medicine administered by therapists, would help to ease suffering for the unwell, what the insights reveal about the mind are equally useful for the well. In studies where healthy people were given a psychedelic, many described their experience as mystical. The mystical experience is represented by many factors which include a sense of awe, attainment of insightful knowledge and the fusion of the personal self into a larger whole.
After these experiences, people come away feeling more grateful for being alive, they implement what they’ve learned to make changes in their behaviour and they feel that they’re not a small separate entity in the universe but that they’re part of it. They escaped the prison of perception and now have new meaning in their life.
Experiments into psychedelics “offer hope of nothing less than a sacralisation of the natural and social world, a spiritual revival that is our best defence against not only soullessness, but against religious fanaticism”Michael Pollan, from How to Change Your Mind: The New Science of Psychedelics
Psychedelics, therefore, teach us that there’s a network in our brains that when working excessively, leads to mental suffering. Studies show that meditating, praying and fasting have a similar effect on our brains. If we learn to quieten our DMN, we may feel less of the existential discomfort from feelings of isolation and meaninglessness. No longer prisoners to our perception, but free wills to control how we experience life.