Possibly the best thing Tom Robbins has ever written, tucked right up at the front of Even Cowgirls Get the Blues: "The brain, that pound and a half of chicken-colored goo so highly regarded (by the brain itself), that slimy organ to which is attributed such intricate and mysterious powers (it is the self-same brain that does the attributing), the brain is so weak that, without its protective casing to support it, it simply collapses of its own weight."
Richard Powers's most recent novel, The Echo Maker, is all about brains and brain damage, and so it's about perceptions and self-deception, and so in many ways, it's also about the act of reading. Mark Schluter, The Echo Maker's main character, suffers from Capgras syndrome, a rare condition caused by brain damage: Once he emerges from a coma, he believes against all evidence to the contrary that his sister, his friends, and even his dog have been replaced by clever duplicates sent as agents of a weird conspiracy. He thinks his home has been replaced by an exact replica and moved several inches to the side.
There's an Oliver Sacks stand-in in The Echo Maker, too, a world-famous neurologist author named Gerald Weber who flies into small-town Nebraska to take a look at Schluter. The sections of the book devoted to Weber are populated with other victims of brain damage as well. A woman suffers from akinetopsia, which causes the sufferer to view the world in a series of still images rather than one fluid reel of film: "A turn of her head launched a series of clunking carousel slides... Her pet cat terrified her, blinking out and materializing elsewhere. The television stabbed at her eyes. A bird in flight made bullet holes in the windowpane of the sky." After reading the full passage, you can't help but experience your own, sympathetic case of akinetopsia. For a second, your brain mimics its own injury.
When your only sensory device is wrong—at one point in the book, Schluter compares his neurons to a group of lost and wandering Boy Scouts with malfunctioning flashlights—there's genuine terror, but also the mystifying sensation of touching down on a completely alien world, a sense that Powers maintains for nearly 500 pages.
Reading is an activity that takes place entirely in our own heads, which is the one place where nobody else can ever really be. There's something miraculous in reading a book—the direct transmission of an extended scenario from one bit of chicken-colored goo to another—but that miracle is always flawed: Little bits of ourselves get mixed in with the characters, and we'll never truly know what shade of blue the sky is in Richard Powers's mind. We read, as we live, at the mercy of damaged instruments. 
Richard Powers gives a Seattle Arts & Lectures talk on Wed March 5, Benaroya Hall, 7:30 pm, $10–$27.
