Perhaps cause and effect are reversed. Measuring young people, many whom are college students shows they stop learning when they leave college - not surprising.
Neuroscience researchers are a little more rigorous than your giving credit for.
When they want to test learning they find people that don't know something, teach it to them, and test them at all points in the process. They also don't limit themselves to a single type of skill and can measure improvement based on how much they improve over time to measure long term skills acquisition.
Hm. "Don't know something" is not a rigourous state at all. Associations are how we know something; older students have more of them.
Unless they limit themselves to reflex action or some such, it becomes impossible to separate previous learning of anything complex.
I think I give researchers plenty of credit. But they don't often have the time/resources to have many/any controls. When a remarkable correlation appears (like 'students stop learning about when they leave school') I call foul.
