The prefrontal cortex is involved in top-down processing that allows control or suppression of reflexes.

“the prefrontal cortex has this amazing ability through what's called top-down inhibition to quiet other brain areas so for instance if you are feeling agitated but you need to sit still your ability to sit still even if it takes a bit of work is coordinated by your prefrontal cortex sending inhibitory suppressive electrical signals to the networks of your brain that are trying to generate physical action in addition to that if you are in a conversation that's either a difficult one or a boring one or you are tempted to interrupt and you are actively holding back your desire to walk away or to yawn or to blurt something out it's your prefrontal cortex that is controlling that active suppression”

“what do I mean by that well if we take a step back and say what is the prefrontal cortex really doing the prefrontal cortex has this amazing ability through what's called top-down inhibition to quiet other brain areas so for instance if you are feeling agitated but you need to sit still your ability to sit still even if it takes a bit of work is coordinated by your prefrontal cortex sending inhibitory suppressive electrical signals to the networks of your brain that are trying to generate physical action”