Explain the process of classical conditioning.

Classical conditioning occurs when a stimulus (UCS) that causes a reflex (UCR) is paired with another stimulus that normally has no effect. After pairing, the second stimulus (CS) causes the same response (CR). A very famous example of this was shown by Pavlov's dogs. Researchers would present the dogs with food (UCS) and pair this with the sound of a bell (a stimulus that would normally have no effect). After repeated exposure, the sound of the bell alone (CS) caused the dogs to salivate (CR). Classical conditioning can occur naturally as well outside of the lab. For instance, try to remember the last time you ate something that had an adverse effect on your well being. Did you avoid this food in the future? This is known as 'conditioned taste aversion' and demonstrates how the previously neutral stimuli (food) becomes a conditioned stimulus that elicits a conditioned response (adverse reaction).