Reflexes

Reflexes are a fast, automatic response to a stimulus that can protect us from harm. For example, a muscle could contract to pull your hand away from a flame. The message does not reach the brain, instead it passes through a relay neuron in the spinal cord, along a route known as a 'reflex arc'.

A learned reflex is called a 'conditioned reflex'. This was discovered by Pavlov when he found that he could make dogs drool by ringing a bell. This was because they had learned that the bell (a secondary stimulus) signalled food (a primary stimulus). Some predators develop a conditioned reflex not to eat brightly coloured insects because they are poisonous.