Before ConditioningBefore conditioning the dog does not associate the bell with food. It will only start salivating after the food appears in front of it. Therefore the unconditioned stimulus results in a unconditioned response.
During conditioningDuring conditioning the dog will start to associate the bell with the food when it is brought out at the same time and will start to salivate . Therefore neutral stimulus produces unconditioned response
After ConditioningAfter conditioning the dog with completely associate the bell and will start to salivate as soon as it hears the bell ring. Therefore, neutral stimulus results in a conditioned response.