Here's how it works.
Ne is a perceiving function, so you don't make decisions with it. It just feeds you data - a certain kind of data. What Ne does, basically, is pattern recognition. You see a cloud of dots and you are asked what the dots represent, and quickly see a face and say, "A face." And indeed, it was a face. You see a bunch of broken lines and say, "A bike." And that is indeed the correct answer (for the purposes of this example, let's just assume the tests have right and wrong answers, and you keep getting them right).
Ne 'fills in the gaps' with quick understanding. But it doesn't tell you what to do with what it gives you. If you're a quiet person, that's because you are using your judging functions to make a decision to be quiet. I'd look into your judging functions to figure out why you are so quiet, because it does not come from Ne.
Ne isn't loud or quiet, but someone with Ne dominant is more stimulated by discovery and innovation than anything else, so naturally they will use their judging functions to support the purpose of their dominant function. Whatever it is that their dominant function does best, all the other functions act as tools for, augmenting and enhancing it.
Your motivations, however, as in - what you feel or think you ought to do with the data given to you by Ne, comes from your feelings and thoughts, your judging functions. Someone with an extraverted dominant function can be immensely shy, never go out to parties, and test as an introvert on personality tests every time. They might never know they were an extravert, not unless they felt or thought they ought to be extraverted. Of course, someone with a dominant extraverted function is far more likely to be outgoing, because to do so would be more supportive of their extraverted dominant function, but not necessarily so in every case.
I, for example, come across to most people as an introvert because I spend so much time at my house on my computer. But if you step into that world, you quickly find that I spend all my time on my computer socializing, and interacting with people or events, playing multi-player games, doing things that involve more than just myself. It took me a while to figure out that I was extraverted, also because I was raised by my grandmother, who is an ISFJ, and so my primary function is her inferior one, and as an introvert she was always trying to shelter me from the world, and that made it difficult for me to adapt to social norms and behaviors, so naturally I gravitate towards situations where I can express myself without fear of reprocussions - but that doesn't make me an introvert, because I'm still primarily looking for ways to express myself - to express my Ne visions and insights.