Human existence has persevered over the years thanks in part to our ability to recognise patterns. Our evolutionary ancestor’s abilities to respond to patterns in the environment around them helped them survive long enough to reproduce and pass on their learnings so the next generation could do the same. From recognising natural cycles in food growth, to identifying the sounds and behaviours of concealed predators, we are hard-wired to recognise and learn from patterns so that we can master our environment and thrive.
This ability to recognise patterns continued long through our evolutionary journey. As we moved from solitary hunter-gatherers into tribal groups, the ability to recognise patterns in facial features helped us identify who was part of our tribe, and who was a threat from outside. This important cognitive skill continued into processing sounds, developing speech and understanding emotional states, features that allowed the modern human to create societies and shape the world as we know it today.
As the human brain progressed, many of these abilities to identify patterns became subconscious reactions, based on biases formed from the consistent correlation of varying inputs. By evolving the skill of pattern recognition to a subconscious process, the human brain has freed up ‘resources’ to use on other tasks. Now, we are constantly forming assumptions and systems deep in our subconscious to build models which we rely upon up to navigate the world.
These models are built on the constant sensory inputs our brain receives. For example, your brain will stop you from stepping out in front of a car if it hears approaching engine noise when you are looking in completely the opposite direction because it has built a model that associates the sound of engines with the threat of impact. Even if that noise is simulated it is likely that the model would predict danger from that sensory input and cause a reflexive reaction to stop walking based on its predictive assumption that engine = threat.
As well as allowing us to navigate our surroundings, these models also influence our beliefs, moods and behaviours. Our evolved brain applies this modelling to our personalities, characteristics and views. Over time, if the input into these models remains relatively consistent, then the model becomes stronger and dominant, going on to influence our behaviours.
This mechanism can be seen in countless human behaviours and actions. Take for example the memes and self-help tips encouraging us to manifest our way to new horizons. Here were are consciously feeding our brain new input in the hope we can influence outcomes through subconscious actions. If a child is raised to hold prejudices against certain races, genders or members of society, those prejudices will often be carried into adulthood without much conscious thought. When a member of a workforce has been completing the same task repetitively for years as part of a job, it can be difficult for them to adopt a new working practice. We are hardwired to resist these changes because it is a threat to the subconscious patterns we have identified that, evolutionarily speaking, have kept us alive. Resistance to change comes from the amygdala, the brain treats it as a threat.
While these models are built upon in the brain over time, they are constantly being updated with any new input. Return to the example of engine noise. On my first encounter with a Prius, I was nearly knocked over. Looking right and stepping out from behind a large bin, I was unaware of the approaching car on my left because I did not register the sound of the much quieter electric car as a threat. Five years later my model has been updated with new information thanks to the proliferation of electric cars. My brain has updated my model and biases thanks to the introduction of new sensory input, I am not consciously listening for an electric car approaching on my blind spot while crossing a road, but I’m subconsciously aware when one is there and I am still alive thanks to my brains model which has to adapt to avoid me ending up sprawled out in front of a Tesla.
What do psychedelics have to do with all of this?
Anyone with experience of taking psychedelics in the pursuit of fun or enlightenment will have experienced a classic trope of finding something seemingly normal fascinating, only to return to base level and realise that the mug, in reality, wasn’t infinitely deep or the ceiling wasn’t dripping multicolour liquids. When we take psychedelic drugs, it is proposed (by R. L. Carhart-Harris and K. J. Friston) that our brain begins to lower its confidence in the models it holds. Take a small dose of mushrooms, and you know the walls are breathing because you’ve taken a psychedelic drug, but take a higher dose and you begin to question what is happening to you at that moment in time. Anyone who has experienced larger doses of LSD, mushrooms or other drugs will share war stories about how reality, time and self-awareness slipped through their fingers like grains of sand as our brains wrestled with the overwhelming new inputs caused by the psychedelic substances. Quite simply, our brains no longer hold confidence in what we believed to be true.
It is the elasticity in our brains model building and sensory processing that makes psychedelics such a promising drug for treating depression and changing other challenging behaviour. In the paper REBUS and the Anarchic Brain, Carhart-Haris and Friston propose that in the midst of a psychedelic experience, our long-held beliefs are less stable and influential on our conscious thoughts because the inputs our brain rely upon to build and hold the models are experiencing vastly new data; it becomes easier to challenge the perspectives we believe to be true because the psychedelics are challenging the models we’ve held on to.
If we look at depression or other negative thoughts and beliefs as being built up from the evolutionary patterns that helped us survive, then we can start to consider that depression could just be an evolutionary by-product, a model built up from inputs of negative self-perception, pessimism or traumatic experiences. Once these models become dominant, our amygdala response resists changing them. Indeed it is proposed that our beliefs may tighten when threatened with some degree of uncertainty, making those negative ruminations harder to shift as they become more common.
Thanks to the certainty of these models in the brain and the reluctance to challenge them, it can be difficult to change embedded beliefs. Existing drug treatments for depression do little to challenge models, only placate or numb the effects. Whereas with psychedelics, combined with the right type of therapy, we have an opportunity to change the beliefs the models support. Indeed, the paper referenced here and the underpinning inspiration for this article uses the acronym REBUS or RElaxed Beliefs Under pSychedelics, inferring that psychedelics and the right therapy and care can rapidly relax problematic beliefs in favour of new ones.
There is much anecdotal evidence that psychedelics have already been used in these ways. The counterculture revolution of the 60s and 70s saw the rapid breakdown of societal norms; patriotism and support for military action in Vietnam was rapidly eroded in the USA thanks in part to the proliferation of LSD and psychedelic culture. Countless stories can be heard around the world of people dropping inherited racist perceptions thanks to enlightening experiences on LSD, mushrooms or MDMA. Psychedelics have even been used in nefarious conquests by cults such as The Family in Australia, where recruits, under the influence of LSD were brainwashed to believe their leader was a religious icon, with great effect.
These theories are fuelling research to prove the potential psychedelic drugs have when it comes to treating depression. Recently, a study carried out by researchers at the Centre for Psychedelic Research at Imperial College London found that psilocybin was at least as effective as a leading antidepressant medication in a therapeutic setting. Parker Singleton, a PhD candidate at Cornell University in New York, recently led a study to test the REBUS theory, analysing fMRI brain scans of people under the influence of a placebo or a dose of LSD. The study showed that LSD flattens the brain’s energy landscape, allowing for more facile and frequent state transitions and more temporally diverse brain activity. It’s this ‘flattening’ of held perceptions and beliefs that allows us to re-write our thoughts, whether that is about our depression, beliefs or habits.
While the research is exciting and arguably long overdue, it is still in its infancy. Cautious optimism remains around the nature of psychedelics and their role in the future of therapy, but with such compelling research, it is difficult not to be excited. In years to come, many people could benefit from this new approach to mental health; instead of using a blanket to smother the beliefs that hold us back, we can begin to rewrite them for the better.