To illustrate, Heilman uses a typical bear encounter. “The visual system recognizes the bear. The cognitive system says ‘Hey, bears can hurt people.’ This sends a message to the amygdala, an almond-shaped organ in the brain that chemically mediates many external experiences and is responsible for triggering the fight-or-flight response. The amygdala talks to the hypothalamus, which sits just above the brain stem and relays messages to the pituitary gland, a marble-sized organ directly below it. The pituitary gland signals the adrenal glands, and the result is a full-body sympathetic nervous system response—increased heart rate, sweaty palms, and all the rest.
Simultaneously, a message is sent to the locus coeruleus, a storehouse of hormones located in the brain stem to secrete norepinephrine. A small dose of this hormone increases the sensitivity of the neurons in the cerebral cortex, explaining why a certain level of stress can improve performance. (Elite athletes excel here; witness Tiger Woods winning the Masters or Venus Williams winning Wimbledon.) But Heilman says too much norepinephrine actually inhibits the knowledge and problem-solving areas of the brain.
“Increased norepinephrine causes you to focus on the external stimuli, but hinders your ability to create a long-term plan,” says Heilman. “Think of a child with attention deficit disorder. Putting these children on medications such as Ritalin (norepinephrine) allows them to allocate their attention to the teacher.” But when you get into trouble, you want to be in your head. Otherwise, you make stupid mistakes.
Kodikian and Coughlin repeatedly misread reality—failing to find the trail they’d walked in on; hiking in the blazing heat to the wrong rim; and, finally, convincing themselves that they were dying when they weren’t.