This is probably overly obvious, and likely this is exactly the research LeDoux and researchers like him are trying to do, but the info I'd want is cases where the threat response occurs in humans without the feeling of fear, and then cases where humans have the feeling of fear without the threat response. Maybe the threat response is generally needed but not itself sufficient for the feeling of fear, so there's a somewhat straightforward "threat response + X" account of full-on human fear. But maybe there are cases where the feeling of fear occurs without the threat response. In that case the relationship between the threat response and feeling of fear (in humans, or sufficiently human-like animals) would obviously be much more complicated. One general line I find attractive even though it's largely speculative is that forms of access and phenomenal consciousness developed fairly independently of other neural systems like the threat response, and all connections between phenomenal consciousness and those older forms of neural activity and older neural systems are likely due to very recent neural changes in in humans. (Access consciousness is a bit more complicated; don't know what to say about its relationship with older neural systems and activities).