^A How these place cells determine the location of the animal in order to decide when to fire spikes is a complex issue—the rat does not have a built-in GPS to determine its location. What actually happens is that it keeps track of its position by dead reckoning—if I know where I am and I take a step forward, I still know where I am, I’m one step forward of where I was—and learns to associate spatial cues (like landmarks) with those location representations, allowing the animal to reset its representation when lost. For those interested, my earlier book Beyond the Cognitive Map describes this process in great detail.

^B Remember that spikes are 1-millisecond blips, so they are best seen with frequency filters set around 1 kilohertz (changes happening on the order of 1 millisecond). Spikes are usually recorded using filters set from 600 Hz to 10 kHz, which pick up things happening on the order of a millisecond or faster. LFPs are usually recorded using filters set from 0.1 to 400 Hz, which pick up things happening on the order of tenths or hundredths of a second.

^C It is important to note the great care taken by neuroscientists, particularly behavioral neuroscientists, in the treatment of their animals. A distressed animal does not perform tasks well, particularly complicated tasks like those required for decision-making experiments. All animal experiments done in any modern university are required to be approved by an animal-care committee that includes both veterinarians and community activists as well as scientists. This committee is tasked not only with checking the treatment of the animals but also with determining if the experiment being done is “important enough” to justify the use of the animals.

^D The brain is a very energy-costly component of your body. Even though your brain is only a couple of percent of your body weight (a typical brain weighs a little less than 1.5 kg [3 lbs]), it consumes about 20% of your typical energy reserves.²⁴

^E This is the key to baseball—a 100-mph pitch takes 400 milliseconds to reach the plate. This means that a batter has about less than half the distance between the mound and the plate to decide whether or not to hit the ball and to determine where the ball will be and when it will cross the plate. Of course, if a batter can predict what pitch is going to come before the pitcher throws the pitch, the batter can be better prepared to recognize the pitch. This is the essence of intelligence—using information and expectation to help make better decisions quickly.

^F Actually, in a stroke, several damaging processes occur over the course of minutes to hours to days. One of those processes is that the decreased blood flow can mean that cells fall out of balance and start to fire at high rates, which drives the cells to death. Treatment that can reach the cells before they die can help reduce or even prevent brain damage due to stroke.²⁷

^G Sensory and motor systems cross in the brain. Thus, the left visual field and the left hand are both processed by the right side of the brain. What, in the evolution of the systems, drove them to cross is still being debated, but there is some evidence that early prey animals have direct connections from sensory systems to the opposite-side muscles.²⁹ If something is coming at you on the left side, you want to go right fast!

^H The safety of TMS is still being debated.³⁶ For most people, it seems that the short-term effects wear off pretty quickly, but the long-term effects are still unknown.

^I It should be noted that we have been able to manipulate genes for thousands of years through selective breeding.³⁸ Humans bred dogs to be more friendly, cows to give more milk, and corn to be edible long before modern genetic manipulations. Modern technologies just make the manipulation more direct.

^J If you still need convincing at this point that the mind exists within the brain, this is the final proof. Manipulating the spiking of cells within the brain changes the perception, the decision, and the action taken. We truly are physical beings.