Saturday, 3 November 2012

Magic mushrooms in the neuropsychoanalytical framework

This week, researchers from Imperial College London publish two separate studies of the effects of psilocybin, the psychoactive ingredient of magic mushrooms. The first appeared in Proceedings of the National Academy of Sciences on Monday, and I've written a news story about it for Nature. It's one of a small number of studies using brain scanning to examine the neurological effects of the drug. The second, published in the British Journal of Psychiatry, examines the effects of the drug on the quality of recalled memories. The past decade has seen a resurgence in psychedelic research, not least because psilocybin and other psychedelic drugs have potential therapeutic value for various psychiatric conditions. Here, I'd like to focus on another aspect of the new studies. Robin Carhart-Harris, lead author on both of the papers, interprets the findings within the framework of neuropsychoanalysis. I briefly describe this emerging movement, and how it might be used to explain the psychological effects of psilocybin. According to Freud, the self consists of three components – the Id, which is driven by instincts and the pleasure principle, and seeks immediate gratification; the Ego, which is driven by the reality principle, and is concerned with making rational decisions; and the Superego, which is driven by perfection and makes moral judgements. The Ego is torn between the demands of the Id and those of the Superego, and uses various defence mechanisms, such as repression and neuroses, to resolve these conflicts. Freud also distinguished between two different modes of thought, which he referred to as the primary and secondary processes. The primary process occurs during abnormal states such as dreaming and psychosis, and is characterised by an excess of neuronal or psychical energy as a result of the Id's actions. The secondary process, by contrast, equates to 'normal' consciousness, and involves the efforts of the Ego to minimize the psychical energy generated by the Id. As Carhart-Harris explains in this talk at the 2010 MAPS Psychedelic Science conference, neuropsychoanalysis attempts to link some of these concepts to large-scale brain networks and their organizational principles. The Ego, for example, equates to the default mode network, a diffuse brain system which comes online during wakeful rest periods, but whose activity is suppressed when the brain engages in a task. Incorporated into this framework is Karl Friston's free-energy principle of brain function. According to this, the brain is an inference machine which makes predictions about the world and modifies them depending on actual experience. It acts to minimize the errors in its predictions, so that they are as accurate as possible. Free energy is thus a measure of the brain's prediction errors, and equates to Freud's concept of psychical energy. In their neuroimaging study, Carhart-Harris and his colleagues found that psilocybin produces widespread decreases in brain activity. "The decreases in activity were in specific regions that belong to… the default network," he told TIME Magazine's Maia Szalavitz. "There's a lot of evidence that it's associated with our sense of self — our ego or personality." He goes on to say that psychedelic drugs often produce "a temporary dissolution of [the] ego or sense of being an independent agent with a particular personality." From the neuropsychoanalytical perspective, then, the effects of psilocybin and other psychedelics may be explained as follows. The psychedelic state is an abnormal state of consciousness, and so can be thought of as akin to Freud's concept of the primary process. Psychedelic drugs act directly on the ego by inhibiting activity in the default mode network, leading to the commonly reported dissolution of the self. By doing so, they unleash free energy that the brain normally tries to keep to a minimum, leading to intense sensory impressions that are not normally perceived, and to uncontrolled thought process. This is, of course, all entirely theoretical and highly speculative, and it's up to proponents of neuropsychoanalysis to show that the framework is more than just a set of metaphors for brain function. What's more, it's still not clear if these new brain scanning data will hold up. As discussed in my news story, Franz Vollenweider and his colleagues at the University of Zürich have just completed a number of similar studies, in which they obtained completely different results, so my neuropsychoanalytical explanation of the effects of psychedelics may be completely wrong.