Here’s a great video from the guys at Crash Course (an awesome Youtube channel covering all sorts of Biology, US History and other college course content). The video covers “conditioning” which is what the famous “Pavlovian response” comes from. It goes further into conditioning and associative learning: how we form relationships with different stimuli and learn cause and effect.
Check it out at https://www.youtube.com/watch?v=qG2SwE_6uVM
And if you’re interested in this or other bits of Psychology or just need 3 fun credits, check out StraighterLine’s Introduction to Psychology.