Amos Zeeberg, Jonathon Keats, and Brandon Keim, write: The Venus flytrap, like most people in the Internet age, has about a 30-second attention span. But that’s a blessing for the carnivorous plant, which relies on memory to survive. The lobes of the plant are laced with three or four “trigger” hairs. When an insect enters the plant and rubs the trigger hairs, the lobes snap shut and the plant consumes its prey. Each stimulation generates an electrical charge, but it generally takes two charges to spark the electrochemical signal that triggers the closure, so the plant must “remember” the first charge as it waits for the second. It has only enough energy to remember for about 30 seconds, so its survival depends on short-term memory and the ability to forget. Similarly, in a human brain, a neuron builds up an electrical charge when stimulated by other nerves, approaching a threshold above which it will fire an electrical signal — the basis of everything from recognizing a plant, like a Venus flytrap, to contemplating the meaning of life. [Continue reading…]