Humans have sophisticated, highly evolved brains that would be useful in directing all body activities. Yet we have the autonomic division and reflexes that intentionally bypass the conscious centers of the brain and directly handle some responses

Question

Evaluate why this is useful. Also, propose situations to the contrary in which it might be useful to use the brain rather than an autonomic response, and explain why we respond as such anyway.

What will be an ideal response?

Answer 1

As remarkably fast as the brain works, it still takes time (even if a small amount of time) for a stimulus to pass from one neuron to the next. As small as the synaptic cleft is, it still relies on the relatively slow process of diffusion for the neurotransmitters of one neuron to pass a signal on to the next neuron. Reducing the number of neurons in a chain from stimulus to response may save that half-second or so that could mean the difference between falling and catching our balance. Additionally, there are some situations in which the response to a stimulus is unambiguous, and there is no reason to involve a decision-making process. Some of the simpler aspects of compensating for unbalanced movement to prevent falling or of being able to pull away from a burning object that is doing more damage every fraction of a second we are in contact with it are examples in which decision making in the brain would hardly ever be useful.
On the other hand, there are rare situations in which overruling a reflex would be useful, and we are largely powerless to do so. Many people would gladly endure an extra split second of pain in order to place, not drop, that expensive antique vase that has a sharp burr that has cut our hand. Something innocuous that has nonetheless startled us and sent our fight or flight response into overdrive would be preferable to ignore. Yet, in the evolutionary balance sheet, being over-prepared for such responses must have been of greater survival value than not having those reflexes and autonomic responses.