One very interesting psychology subject is classical conditioning. This is a type of learning in which an organism learns to associate stimuli. There are many classical examples of this. Pavlov had a very interesting experiment in which he would make a dog salivate at the playing of a tone.
I also had a similar experience to classical conditioning with my own dog. Although this time, the conditioning was by accident. I have a yellow lab at home and to this day, she loves to bark at animals on the TV. She for some reason still has not figured out that they are not real. So when the K9 Advantix commercial came out with the cute puppies running around and a catchy jingle, my dog would love to bark at it. She began to see this commercial more and more and still would bark at it every time. It got to the point where she would hear the jingle, and just automatically start barking as soon as she heard this. She didn’t even need to see the actualy commercial she only needed to hear it. There were actually times when she would be in another room when the commercial would come on and she would come running out into the living room to bark at the TV because she knew their would be dogs on it. This is a great example of classical conditioning, even though it was not on purpose. The unconditioned stimulus was the commercial itself with the jingle. The Unconditioned response was her barking at the TV because of the dogs running around. The conditioned stimulus was the jingle itself on the commercial. And the Conditioned response was when she learned to associate the jingle with the commercial, she would then come barking out to the TV even though she had not seen any dog on the TV, she only needed to hear the sound of the jingle now.