I'm helpless at biology/science-y stuff in general. But, as a writer, for the sake of story research, I often have to delve into it. I make use of the Worldbuilding Stack Exchange, but this question didn't seem like it would be a good fit for that site, because it's more about clarifying my understanding of certain scientific concepts than about anything specifically worldbuilding related.
I am looking to create a character with high-speed reflexes and reaction time. However, my question is not about how to accomplish this (scientifically dubious) feat, as this would belong on the worldbuilding forum, but rather whether I have properly identified the elements necessary to do so.
From the research I've done, it seems that the most basic steps regulating how quickly someone reacts to something are a) sensory neurons recognize a stimulus b) they send a signal to the brain/spinal cord and c) this signal is processed and another signal is sent to the muscles, resulting in whatever physical reaction observably occurs.
Hypothetically, then, no matter how fast any single element in this chain (if given a brain that could process signals 10x faster than normal or nerve signals that traveled 10x faster (bear with me)), the speed with which the final action was triggered and completed would still be limited by, say, the eyes' tracking speed and the speed with which the eye converted light into electrical signals on one end, or the speed the muscles were capable of contracting at the other end of the chain.
How am I doing so far?
So, by my estimation potential limiters of reaction speed are as follows:
the speed the eye moves (or would speeding up other things, such as muscles and nerve signals, also increase this?)
the speed the eye converts light into signals
the speed that signals can travel from sensory neurons to the brain/spinal column
the speed with which the brain can process these signals (and potentially its ability to handle multiple tasks/stimulus simultaneously)
similar to (3), the speed that signals from the brain (or spinal cord) can travel to the muscles
the speed with which muscles can contract
Am I confused about or missing anything? Thank you!