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Larger organisms explore a wider world and live longer, thereby expanding their possibilities for foraging but also their exposure to danger. Now a bigger brain becomes essential for sensing the environment and guiding behaviour. Behaviour must satisfy an animal’s internal systems, and internal systems must support behaviour. Thus the brain’s core tasks are to adapt behaviour to conditions and to match internal systems to these conditions, thereby using resources efficiently. These tasks involve gathering and transmitting information, defined by Shannon’s equations and quantified as the unit, bit. To capture, send, or store a bit costs space and energy, and for fundamental reasons higher rates are disproportionately expensive. Therefore neurons are constrained by three principles: send only information that is needed; send it at the lowest possible rate; minimize “wire” (minimize length and diameter of all neural processes). These few principles explain many design features of bigger brains – as exemplified in Chapter 4.

Our brain outsmarts a supercomputer while using 100,000-fold less space and energy. It succeeds by hugging the linear region of the information rate vs. cost curve. The ways to do this constitute principles of neural design: improve S/N; reduce redundancy; sculpt messages to send only what is needed; send via parallel channels to match capacity to natural distribution of information. These strategies help to send at the lowest acceptable rate. Neurons compute cheaply using chemical diffusion and allosteric binding in irreducibly small compartments. Chemistry and local electrical signalling are analogue processes, which are efficient but noisy. Therefore, they couple to mechanisms for thresholding that remove noise and convert to pulses that travel rapidly over distance. Because pulses are costly: information is concentrated to improve bits per pulse; rates are restrained; and wire is minimized by strategic layout. By adapting/learning, the brain becomes the computer needed for the next task at lower cost than an all-purpose machine. The principle, separate computations in different areas and different hemispheres, extends to separating skill sets in different brains within a community – requiring circuits for cooperation. This strategy implies the need for flexible education to allow children with different skill sets to develop them.

The stock narrative of the Industrial Revolution (ca. 1760–late 1800s) is one of moral and economic progress. Indeed, economic progress is cast as moral progress. The story tends to go something like this: inventors, economists, and statesmen in Western Europe dreamed up a new industrialized world. Fueled by the optimism and scientific know-how of the Enlightenment, a series of heroic men—James Watt, Adam Smith, William Huskisson, and so on— fought back against the stultifying effects of regulated economies, irrational laws and customs, and a traditional guild structure that quashed innovation. By the mid-nineteenth century, they had managed to implement a laissez-faire (“free”) economy that ran on new machines and was centered around modern factories and an urban working class. It was a long and difficult process, but this revolution eventually brought Europeans to a new plateau of civilization. In the end, Europeans lived in a new world based on wage labor, easy mobility, and the consumption of sparkling products. Europe had rescued itself from the pre-industrial misery that had hampered humankind since the dawn of time. Cheap and abundant fossil fuel powered the trains and other steam engines that drove humankind into this brave new future. Later, around the time that Europeans decided that colonial slavery wasn’t such a good idea, they exported this revolution to other parts of the world, so that everyone could participate in freedom and industrialized modernity. They did this, in part, by “opening up markets” in primitive agrarian societies. The net result has been increased human happiness, wealth, and productivity—the attainment of our true potential as a species! Sadly, this saccharine story still sweetens our societal self-image. Indeed, it is deeply ingrained in the collective identity of the industrialized world. The narrative has gotten more complex but remains a la base a triumphalist story.