Trouble in Mind: An Unorthodox Introduction to Psychiatry

2. Elementary Mind

chapter two Elementary Mind The mind has two main sources of input: sensation, stimulated by the environment, and arousal, stimulated by signals from the body. The mind has one main conduit for output: orchestrated skeletal muscle contraction . To make sense of the world, to respond to bodily needs, and to move effectively in the environment, these elemental strands of mental life must come together. When they do, they generate information: an emergent phenomenon connecting the physical properties of the world we inhabit to the biochemistry of our bodies. Emergent phenomena have properties that cannot be adequately explained in the same language and logic that explains their simpler mechanisms. All subatomic particles obey the laws of physics, but the laws of physics are overmatched by even simple phenomena contained in the periodic table, such as the fact that fluorine (atomic number 9) has properties more in common with chlorine (number 17) than with its immediate neighbor neon (number 10). Brains obey the laws of physics and biochemistry, but when our brains attach personal significance to the phenomena we observe, the urges that move us, and the things we do, we add something to the world that would not have 30 Trouble in Mind existed without cerebral processing, and which cannot be reduced to the physics of light, sound, and pressure transduction and the biochemistry of sodium ions and serotonin. How do we manufacture information from the raw materials of cerebral activity? How, for example, do we transform a fleeting retinal flicker into the image of a soaring bird? The short answer is, we can’t, without the help of the other elementary aspects of mental life. Nor can we interpret hunger pangs as a yen for pistachio ice cream, based solely on the quality of the visceral sensations. Nor can we differentiate picking up a baby from lifting a sack of potatoes, using only the sequence of motions we undertake. Somehow we must learn how to identify what we perceive, pursue what we need, and act with purpose. The mind is more or less a blank slate at birth, though the tabula is not quite rasa. Our brains do come equipped with sense-specific virtual maps, embedded in the cortex and subcortical structures. The first bit of information we can derive from sensation thus consists of the locations within the brain, down to specific sets of neurons, which immediately become active at an encounter with a specific stimulus. The final bit of information output consists of the specific arrays of cortical neurons in the motor strip that, at any given moment, send signals out to the muscles they control. But none of this is useful to the naïve neonate. Sensations reach the newborn cortex with minimal organization and thus with little value as a source of information. Infantile movements appear uncoordinated, if not random. The capacity for organization and coordination depends on neuronal maturation , but also on rich encounters with the environment. Hubel and Wiesel, in their classic experiments (Hubel 1982), demonstrated that kittens, blinded temporarily for several weeks after birth, fail to develop full visual perception after the blinders are removed. Therefore, sensory stimulation must play a critical role in the organization of raw input into useful perception. Learning to draw information from experience is not as simple as filling an empty vessel with knowledge—we not only lack knowledge at birth, we lack the vessel to hold it. Eventually, when we become sentient beings, we grow adept at dialectical learning. We start with some bit of information (thesis), note when it fails to be true (antithesis), and from that we acquire a more sophisticated body of knowledge (synthesis). But how can an infant imbue the world and body with information, when there is no information to begin with, no thesis as a point of reference? The answer, as will be described in the Elementary Mind 31 following sections, is that the information content of something we sense develops from the arousal state of the body at the time we sense it, and from the way our sensory experience and body state changes as a result of the things we do when we sense it. A few words on terminology, before moving on. Sensation is not the same as perception, and motion is not interchangeable with action. Sensation refers to the raw cortical representation of the physical properties of the world. Perception...