Bulk And Skull Quotes

Our desire to segregate the mind’s cogitations from the body’s exertions reflects the grip that Cartesian dualism still holds on us. When we think about thinking, we’re quick to locate our mind, and hence our self, in the gray matter inside our skull and to see the rest of the body as a mechanical life-support system that keeps the neural circuits charged. More than a fancy of philosophers like Descartes and his predecessor Plato, this dualistic view of mind and body as operating in isolation from each other appears to be a side effect of consciousness itself. Even though the bulk of the mind’s work goes on behind the scenes, in the shadows of the unconscious, we’re aware only of the small but brightly lit window that the conscious mind opens for us. And our conscious mind tells us, insistently, that it’s separate from the body.

The midwife laid her hand on his thick skull, With this prophetic blessing—Be thou dull; 60 Drink, swear, and roar, forbear no lewd delight Fit for thy bulk, do anything but write. Thou art of lasting make, like thoughtless men, A strong nativity—but for the pen; Eat opium, mingle arsenic in thy drink, 65 Still thou mayest live, avoiding pen and ink. I see, I see, ’tis counsel given in vain, For treason, botched in rhyme, will be thy bane; Rhyme is the rock on which thou art to wreck, ’Tis fatal to thy fame and to thy neck.

These axons can shuttle information around so quickly because they’re fatter than normal axons, and because they’re sheathed in a fatty substance called myelin. Myelin acts like rubber insulation on wires and prevents the signal from petering out: in whales, giraffes, and other stretched creatures, a sheathed neuron can send a signal multiple yards with little loss of fidelity. (In contrast, diseases that fray myelin, like multiple sclerosis, destroy communication between different nodes in the brain.) In sum, you can think about the gray matter as a patchwork of chips that analyze different types of information, and about the white matter as cables that transmit information between those chips. (And before we go further, I should point out that “gray” and “white” are misnomers. Gray matter looks pinkish-tan inside a living skull, while white matter, which makes up the bulk of the brain, looks pale pink. The white and gray colors appear only after you soak the brain in preservatives. Preservatives also harden the brain, which is normally tapioca-soft. This explains why the brain you might have dissected in biology class way back when didn’t disintegrate between your fingers.)

We debated this point until the skull was clear of the bulk of its flesh. As I began sketching again, he asked me, “What do you think? Taxonomically.” “It’s difficult,” I admitted. By then my hand was capable of going about its work without demanding all of my attention; I could ponder issues of classification at the same time. “The dentition bears some similarities to those reported or observed in other breeds, at least in number and disposition of teeth … though of course baleen plates are not a usual feature. The vertebrae certainly pose a problem. This creature has quite a lot of them, and we do not usually consider animals to be close cousins who differ so greatly in such a fundamental characteristic.” Tom nodded, wiping his hands clean—or at least less filthy—with a cloth. “Not to mention the utter lack of hind limbs. I saw nothing in the dissection, not even anything vestigial. The closest thing it has to forelimbs are some rather inadequate fins.” “And yet there are similarities. The generally reptilian appearance, and more significantly, the degradation of the bones.” I thought of the six criteria customarily used to distinguish “true dragons” from draconic creatures: quadripedalism, flight-capable wings, a ruff or fan behind the skull, bones frangible after death, oviparity, and extraordinary breath. We might, if we were very generous, count the serpent’s supraorbital tendrils (presuming it had once possessed them) as the ruff, and Tom had just confirmed that the creatures laid eggs. Together with the bones—which decayed more slowly than those of terrestrial dragons, but did become frangible quite rapidly—that made three of six. But was there any significance to the distinction between “true dragons” and their mere cousins? What if there was only one characteristic that mattered?

Receptor neurons bundle together into cables called axons, feeding up through holes in a perforated bone just behind the eyeballs called the cribriform plate. (In a serious head injury, the skull can shift, and the lateral movement of the cribriform plate shears those axons like a knife through spaghetti. Snip! No more sense of smell.) Once through the plate, the axons connect to two projections from the brain called the olfactory bulbs. There, in blobs of neurons called glomeruli, is where the bulk of the computation gets done. Mice, known for their acute sense of smell, have just about 1,800 glomeruli—but 1,000 genes that code for olfactory receptors. That’s a lot of perceivable smells. Humans have a seemingly pathetic 370 genes for receptors, but we have 5,500 glomeruli per bulb. That’s a lot of processing power. It must be doing something. The part of the brain that integrates all this information, the olfactory cortex, also gets inputs from the limbic region and other areas that deal with emotion—the amygdala and hypothalamus, among others. Processing of smells in the brain, then, is tied to not only the chemical perception of a molecule but also how we feel about it, and how we feel in general. Every other sense in the body is, in a way, indirect. In vision, light impinges on the retina, a sheet of cells at the back of the eye that makes pigments and connects to the optic nerve. In hearing, sound (which is really just waves of changing air pressure) pushes the eardrum in and out at particular frequencies, which translate via a series of tiny bones to nerves. Touch and taste are the same. Some cell, built to do the hard work of reception, gets between the stimulus and the nerves that lead to the brain for processing. Some physical effect—air pressure, reflected photons, whatever—gets between the stimulus and the perception. It’s all a first-order derivative. Not smell, though. When we smell something, we are smelling tiny pieces of that thing that have broken off, wafted through the air, and then touched actual neurons wired to actual pieces of brain. Olfaction is direct, with nothing between the thing we’re smelling, the smell it has, and how we perceive that smell. It is our most intimate sense.

The towering bulk of my stepfather was poised with hand drawn back about to strike the bleeding face of my mother. Fright found a voice: ‘Oh Do-o-on’t!’ I shrieked. ‘Don’t hit her – you leave her alone!’ I felt the raw tremulous sounds heave up from my chest and thought I would vomit. He swung around, his mouth agape, arm still aloft, and stared at me as though I were an apparition … stared at my child-frame vibrating now in a paroxysm of shock. ‘I’ll kill you!’ I promised ludicrously in a high shrill that reverberated in my skull and seemed alien to my ears, and I thought he would do the same to me. But he stopped, took a swaying stride forward and leaned on the dresser and, flinging out the great arm of which I was in mortal terror, he growled, ‘Get t’ bloody bed!