Many people who have had near death experiences report seeing their life flash before their eyes. There are multiple theories as to how this may occur. While some scientists believe this is caused by a surge of electrical activity in the hippocampus before the brain dies, others believe this phenomenon is a result of the brain’s deprivation of oxygen and glucose. Another notable theory is that the stress hormone noradrenaline, released by areas of the brain responsible for mediating memory and emotion causes dying individuals to hallucinate.
Despite the fact that the only thing science can agree on regarding the origin of these experience is that they disagree- there is solidarity in research showing that there’s a scientific reason the phrase “running around like a chicken with its head cut off” exists.
When you die, your brain continues to show activity for seven (or more) minutes.
Of course, I suppose this may not apply when you send a 9 millimeter bullet careening through your skull.