It’s no secret that I and this blog are excited about the return of psychedelic drugs to academic study. After being shut out of the warmth, labelled as criminal and shunned for four decades, finally scientists are yet again investigating the effects of drugs such as LSD, magic mushrooms and DMT. Not only do these drugs hold great potential for helping us understand more about how the brain functions both in normal and altered states of consciousness, they also hold great promise as therapeutic aids in clinical psychiatry.
The Psychologist magazine currently has a free special issue on psychedelics in psychology. There’s lots of interesting stuff there, including an article on how psychedelics exert their effects in the brain. The classic psychedelics such as LSD and magic mushrooms in particular activate the serotonin 2A receptor, leading to a cascade of changes on many levels of the brain:
Much of brain activity is rhythmic or oscillatory in nature and electroencephalography (EEG), magnetoencephalography (MEG) and local field potential (LFP) recordings are techniques that measure the collective, synchronously oscillating activity of large populations of neurons. Studies in animals and humans have found decreases in oscillatory activity in the cortex after the administration of hallucinogens, and in one of our most recent and informative studies with psilocybin we observed a profound desynchronising influence on cortical activity (Muthukumaraswamy et al., 2013). (…)
To help illustrate this principle by analogy, the strength of cortical rhythms can be thought of as analogous to the rhythmic sound generated by a population of individuals clapping their hands in synchrony. The presence of an individual clapper among a population of clappers means that his/her rate of clapping becomes quickly entrained by the collective sound generated by the population as a whole. Now imagine that a number of mischievous ‘ticklers’ are introduced to the scene, inducing sporadic clapping by tickling individual clappers. Although the individuals targeted may be excited into clapping more often, there will be a disruptive effect on the regularity and volume of the sound generated by the population as a whole. The basic principle is that although hallucinogens excite certain excitatory neurons in the cortex to fire more readily, this has a disorganising influence on cortical activity as a whole.
And further, psychedelics have the potential to dissolve the ego, our perception of a continuous self. The mechanism for this seems to be screwing with the so-called “default mode network,” a network of neurons that is pretty much active in the background all the time, helping to maintain our regular sense of ourselves as unitary selves flowing through time:
Evidence has accumulated in recent years highlighting a relationship between a particular brain system and so-called ‘ego functions’ such as self-reflection (Carhart-Harris & Friston, 2010). This network is referred to as the ‘default mode network’ because it has a high level of ongoing activity that is only suspended or interrupted when one’s attention is taken up by something specific in the immediate environment, such as a cognitive task (Raichle et al., 2001).
It was a matter of great intrigue to us therefore that we observed a marked decrease in brain activity in the default mode network under psilocybin (Carhart-Harris et al., 2012) whilst participants described experiences such as: ‘Real ego-death stuff! I only existed as an idea or concept… I felt as though I was kneeling before God!’
The default-mode network is also called the “task-negative” network. It is anticorrelated with the so-called task-positive network. This is a brain network that is highly engaged when our attention is on goal-oriented activity. The anticorrelation means that when one system is highly active, the other is not, and vice versa. Thus we can, to put it in terms perhaps a little too much like pop psychology, literally “lose ourselves” in a task or activity. This comes about because the default mode or task-negative network that is largely responsible—as far as we understand the brain at this time—for introspection and maintaining our sense of self, while the task-positive network which is activated during goal-oriented activity intrinsically suppresses this introspective network.
Thus there are similarities between the psychedelic state and flow states, when we are so engaged in an activity that everything else, including our sense of self, seems to fade away into the background. That, of course, doesn’t mean that flow states and being on LSD are exactly alike—there are many differences too obvious to point out. However, it does indicate that we do in fact enter altered states of consciousness all the time: when we’re deeply engaged in an activity, when we’re asleep or half asleep, and so on. Not just when we’re taking mind-altering drugs or engaging in ritualistic religious rites.
There’s more interesting stuff in the issue, such as third- and first-person accounts of psychedelic treatment, and a look at what famous writers have had to say about being on hallucinogens. There’s also an article by Vaughan Bell on cultural views on chemically induced hallucinations:
The typical Western account of why ayahuasca is consumed usually focuses on ‘getting in contact with the spirit world’, but this fails to capture either the cultural worldviews in which ayahuasca consumption is situated or the motivations behind the ceremonies. The first thing to note is that Amazonian people can differ greatly in how they understand reality in relation to themselves. For example, the Cashinahua, Siona, and Schuar peoples all use ayahuasca as a tool for revelation but differ markedly in how they understand the experiences it produces. The Cashinahua understand ayahuasca as causing hallucinations that provide guidance (Kensinger, 1973), the Siona believe that it allows access to an alternative reality (Langdon, 1979), while the Schuar take all normal human experience to be a hallucination and take ayahuasca as a way of accessing true reality (Obiols-Llandrich, 2009).
Perhaps, then, it’s fitting to end with a quote from one of the most famous writers on psychedelics, Dr. Gonzo himself, Hunter S. Thompson. Thompson regarded himself and his reckless drug use as embodying something of a national archetype:
I am the prototype, the perfect American. Half out of control, violent, drunk, high on drugs, carrying a .44 Magnum. Rather than being strange, I may be the embodiment of the national character…all the twisted notions that have made this country the beast it is.