Optimal Being

We can account for the evolution of consciousness only if we crack the  philosophy, as well as the physics, of the brain. The science of consciousness has not lived up to expectations. Over the summer, the neuroscientist Christof Koch  conceded defeat  on his 25-year bet with the philosopher David Chalmers, a lost wager that the science of consciousness would be all wrapped up by now. In September, over 100 consciousness researchers signed a  public letter  condemning one of the most popular theories of consciousness—the integrated information theory—as pseudoscience. This in turn prompted strong  responses  from other researchers in the field. Despite decades of research, there’s little sign of consensus on consciousness, with several rival theories still in contention. Your consciousness is what it’s like to be you. It’s your experiences of color and sound and smell; your feelings of pain, joy, excitement or tiredness. It’s w...

Animals learn especially well from surprising events, and the hormone noradrenaline may be one reason why. You reach over a stove to pick up a pot. What you didn’t realize was that the burner was still on. Ouch! That painful accident probably taught you a lesson. It’s adaptive to learn from unexpected events so that we don’t repeat our mistakes. Our brain may be primed to pay extra attention when we are surprised. In a recent  Nature  study, researchers at the Massachusetts Institute of Technology found evidence that a hormone, noradrenaline,  alters brain activity —and an animal’s subsequent behavior—in these startling moments. Noradrenaline is one of several chemicals that can flood the brain with powerful signals. Past research shows that noradrenaline is involved when we are feeling excited, anxious or alert and that it contributes to learning. But the new research shows it plays a strong role in responses to the unexpected. The M.I.T. team used a method called optoge...