The Psilocybin Solution

shoots through the neuron is itself chock-a-block with chemical complexity. We find outrageously sophisticated potassium and sodium chemical pumps in the axon; we find vast oceans of charged particles, or ions, being continuously pumped in and out of the axon through special membrane channels so that an electrical current is created; and we witness, finally, the aforementioned emergent wave of electrical activity whizzing along the axon to the terminal fibers and on to the synapses. That is the least that can be said about Nature’s wondrous evolutionary endeavors in crafting the mammalian brain.

In general, a major conceptual flaw in our understanding of the workings of neurons is the distinct lack of appreciation for their relative size and speed of activity, an unfortunate fact that I am at pains to rectify here. Our modes of inquiry tend to gloss over complexity. True, we don’t have to marvel, gasp, and sit down in amazement at neuronal phenomena, yet to not do so (marvel at least) is to overlook the subtlest fruits of the evolutionary process.

So, although we can examine individual neurons and ascertain the mechanism whereby they transmit information, and although we can recognize the role of neurotransmitter substances in propagating information from neuron to neuron through the synapse, traditional scientific approaches tend to fail dismally in fully conveying, in a qualitative sense, the immense organizational complexity involved in the neuronal system as a whole.

Textbooks, for clarity, describe single neurons and single synapses in a fairly cold and reductive manner. What seems never to be stressed is the magnitude of electrochemical changes that zip throughout the conscious brain. Literally billions of coordinated and meaningful molecular events occurring in literally billions of discrete locations at every moment are somehow integrated so that organized sense results. This is information processing with a vengeance!

If, then, we are attempting to marry such neuronal activity with psychological activity (consciousness), that is, if we are attempting to bridge the conceptual gap between mental reality and physical reality, then we must appreciate the organizational complexities involved. If we were merely to skate over the immensity of these processes, we would miss an intuitive feel for the entire system.

Neuronal Patterns and Context

Returning to the concept of organized patterns of neuronal firing, this becomes useful when we consider the way the brain must work in everyday situations. If we take some important psychological function like, say, face recognition, we can see that the particular pattern of neuronal firing caused by nerve impulses issuing from the visual system when it is looking at a face will be, for any particular face, unique. In other words, each face we see will generate a unique pattern of neuronal firing—the face’s neuronal signature—in our brain. Furthermore, the neuronal processing of faces appears to reside in a specific area of the brain that can be selectively damaged, resulting in prosopagnosia, a disorder in which the sufferer fails to recognize faces, even those of close family members.

Similarly, we recognize different people’s voices by virtue of the fact that each voice causes a distinct pattern of neuronal firing that is conducted from the auditory senses to deep within the brain. Eventually this pattern of information reaches that part of the brain where acoustical information is analyzed and recognized. The same is true for different tastes. Each type of food or drink we consume causes a different pattern of nerve impulses to be generated, which finally reaches that part of the brain that deals in the perception of taste.

In each of these cases, the neuronal pattern produced through the sensing of a particular face, voice, or taste will, at some stage, need to be compared with other possible neuronal patterns in order to yield its particular meaning and significance. Therefore, the different processing systems of the brain must act, in part, to provide a context for ongoing neuronal patterns. Without a contextual effect, neuronal patterns would not be able to yield their inherent meaning. The brain’s capacity to provide a precise context for ongoing neuronal patterns is thus crucial in understanding how neuronal activity and neuronal firing patterns become meaningful.

The Berkeley psychology professor Bernard J. Baars has noted the importance of contextual effects in giving meaning to ongoing neuronal patterns. In A Cognitive Theory of Consciousness he writes: “We generally gain information about a world that is locally ambiguous, yet we usually experience a stable, coherent world. This suggests that before input becomes conscious, it interacts with numerous unconscious contextual influences to produce a single, coherent, conscious experience. Consciousness and context are twin issues, inseparable in the nature of things.”^{27}

Although a detailed look at all the intricacies of neuronal firing patterns is beyond the scope of this book, for the time being it is enough that we grasp the essential principles that are likely to be involved in the brain’s processing of information. Organized neuronal patterns arising from, say, visible external stimuli contain a wealth of latent information about the stimuli, which is to say that the neuronal patterns are representations of those stimuli. The latent information in these neuronal representations then gets “read” once the neuronal patterns are contextually processed. The brain, by supplying a context for neuronal representations, is able to access the meaning inherent in them.

One neurophilosophical approach to understanding mental states is that of functionalism, which, despite its dreary name, captures the important role of context in conscious brain processes. Essentially, functionalism views firing states of the brain as playing functional roles in an economy or language of possible firing states, which is another way of describing the type of contextual effects outlined above. Any neuronal firing state of the brain derives its significance and meaning from the functional role that it plays within a language of possible states. All possible states are related to one another (just as all words in the English language are related to one another), and it is the network of relations (stored within the brain’s memory systems) that acts as context.

We now have at least a preliminary handle on the fundamental way that the neuronal brain operates. Patterns of neuronal firing embody information and meaning that is read or accessed by the brain through language-like contextual/relational effects. Conscious experience appears to be intimately bound somewhere within this information-processing system, since it is consciousness that comes to experience meaning. We see faces and we know who they are. We see pictures and we see what they mean. We hear sounds and we know what they signify. Consciousness is therefore substantiated within neuronal information processing, and it begins to look as if consciousness itself is a form of information that emerges at the highest and most integrated level of the neuronal system.

With these speculations in mind, let us look at the way that psychoactive substances influence neurons, synapses, and, of course, consciousness. This is where physical processes can be seen to be connected directly to changes in consciousness, an area of analysis teeming with profound implications, especially when we consider the effects of psilocybin. More important, we might ascertain still more clearly how consciousness can be understood as a form of information.

Chemistry and the Mind

There are drugs and there are drugs. To be precise, there are five principal classes of drugs that alter mood and behavior, some of which we have already met and discussed. There are depressants like alcohol, barbiturates, Valium, and anesthetics; stimulants like amphetamines (speed), cocaine, caffeine, and nicotine; opiates like opium, heroin, and morphine; antipsychotics like chlorpromazine and risperidone; and last but by absolutely no means least, there are psychedelics or entheogens like psilocybin, mescaline, LSD, and DMT. Cannabis and the synthetic club drug Ecstasy (MDMA) are sometimes classified as psychedelics as well.

The substances listed here as psychedelic could be further divided according to the precise effect they have, but this basic classification will suffice for the following discussion, which focuses on the way these substances are believed to work. Although we will briefly look at each class of substance, the most attention will be paid to the known neuro-physiological effects of psilocybin.