Even though her chest is moving to breathe, those muscles relax and some of the air does not pass through. That is called obstructive apnea . It is also something that a preemie will grow out of when the breathing center in his brain matures. That can often be solved by just repositioning him. He may even spit up.
Reflux can set off bradycardia.
That too is something that preemies grow out of. Initially, the brain develops by making a lot of cells and then, depending on what kind of stimulation those cells get, some connections form and get stronger while others disappear. At early ages, during the development of the brain and for several years thereafter, if one part of the brain is damaged, many times, another part can take over its function and the baby not suffer from it. It's true that many brilliant people were preemies, so were normal people and unfortunately, so were some with learning problems. We know that learning problems are more common in preemies, mostly in those weighing less than 1,500 g.