Looking at the question, I agree with the commentator on that point and in general about that question. Probably, a good way to see how is to recognize what philosophy (as the term is now used) is not but cognitive science is. Philosophy (exempting a group that does "experimental philosophy") is not an empirical science. While it was true, in say the era of Francis Bacon, we no longer ask philosophers to answer the empirical part of a question.
e.g., how much does the sun weigh? (actually a flawed question)
OR
at what age do children start using abstract concepts?
OR
what is the maximum possible number of things you can memorize in a day?
Cognitive science might have something to say on the last two and do some brain scans. It may then offer some philosophical (and therefore contestable) interpretations of what those scans and results mean.
So for instance, there are those Harvard brain scans about how people react to racialized language. The empirical part is the delay that is calculated. The philosphical part is what we make of it. The empirical part cannot decide whether people's delays represent a moral problem or even necessarily that they have a bias. So I for instance am not convinced that the studies mean what some of the authors want us to think they mean. I don't dispute what people do in the studies.
To give another example, some studies have shown that people's brains are already decided before they say they've reached a decision. Fair enough. The interpretation that this means that we don't make decisions and morality is bunk is however open to dispute and not really resolvable unless a more dramatic experiment takes place.
To simplify, cognitive scientists often try to do both the empirical science and the interpretative business. Philosophers needn't interrupt the experiments (unless the goal is to ask about the nature of science itself), but they needn't accept the conclusions drawn from interpreting.
