AP BIOLOGY

Detailed explanation-1: -Pavlov was conducting research on the digestion of dogs when he noticed that the dogs’ physical reactions to food subtly changed over time. At first, the dogs would only salivate when the food was placed in front of them. However, later they salivated slightly before their food arrived.

Detailed explanation-2: -Before classical conditioning begins, the unconditioned stimulus (US) produces an unconditioned response (UR) in an individual naturally. This is a reflex reaction that doesn’t require training or practice. It is also called the primary reinforcer.

Detailed explanation-3: -The behavior caused by the conditioned stimulus is called the conditioned response (CR) . In the case of Pavlov’s dogs, they had learned to associate the tone (CS) with being fed, and they began to salivate (CR) in anticipation of food.

Detailed explanation-4: -Most of what we believe we know about Ivan Pavlov (1849–1936), the iconic Russian physiologist, is wrong. He trained dogs to salivate at the sound of a bell. No, he never used a bell; he used metronomes, harmoniums, electric shock or other stimuli that could be measured more precisely.

Detailed explanation-5: -Pavlov (1927/1960) studied unconditioned reflexes with dogs. He found that placing meat powder in a dog’s mouth (US) elicits salivation (UR). The conditioning part of his experiment involved pairing various innocuous stimuli with the food, such that they preceded food delivery.