Do human beings have a magnetic sense? Biologists know other animals do. They think it helps creatures including bees, turtles and birds navigate through the world.
Most animals have brains in proportion to their body size – species with larger bodies often have larger brains. But the human brain is almost six times bigger than expected for our bodies. This is puzzling, as the brain is very costly – burning 20% of the body’s energy while accounting for only 4% of its mass.
Mr. B loves Johnny Cash, except when he doesn’t. Mr. X has watched his doctors morph into Italian chefs right before his eyes. The link between the two? Both Mr. B and Mr. X received deep brain stimulation (DBS), a procedure involving an implant that sends electric impulses to specific targets in the brain to alter neural activity. While brain implants aim to treat neural dysfunction, cases like these demonstrate that they may influence an individual’s perception of the world and behavior in undesired ways.
Given how much they can actually do, computers have a surprisingly simple basis. Indeed, the logic they use has worked so well that we have even started to think of them as analogous to the human brain. Current computers basically use two basic values – 0 (false) and 1 (true) – and apply simple operations like “and”, “or” and “not” to compute with them. These operations can be combined and scaled up to represent virtually any computation.