Halloween 2015 pumpkins jack o'lantern
A Halloween jack o'lantern carved into a pumpkin Getty

With Halloween fast approaching, scientists have explained exactly what would happen to your brain if you were a victim in a slasher film being hunted by an axe murderer. The American Chemical Society released their Reactions video showing the body's response to fear, injury and ultimately death.

Initially, they say, the response would be similar to what you experience when watching a horror film. Fear is a cognitive response alerting you to trouble, gearing up the body to escape any danger.

"When you perceive possible danger, that sensory information is sent through your central nervous system to a region of the brain that works like a switchboard called the thalamus," the film says.

"The thalamus then hustles the signal over to the amygdala using a neurotransmitter called glutamate. Glutamate-based signalling then transmits the emergency to two parts of the brain – the periaqueductal gray and hypothalamus. When the signal riches the periaqueductal gray, it switches you to a state of hyper-alertness and makes you startled."

After this, the fight or flight response is triggered – the adrenal glands start pumping out adrenaline and makes its way to the liver, which releases glucose into the bloodstream providing extra energy needed to escape. This response is kept up and running by the cortisol.

If you escape at this point, that's great. But in horror films, most of the time they do not. So moving on, the Reactions team note that you would probably then scream – a primordial automatic function thought to trigger a fear response in others. "Recent research suggests we perceive screams in a completely different region of the brain than language. Unlike normal speech, screams go from your ears to the amygdala, the brains' emergency centre and can trigger a similar emergency response in listeners. It's almost like the screamer is trying to share with you the state of their horrified brain chemistry."

With an axe murderer unlikely to be put off by a bloodcurdling cry for help, then it is time for injury and death. When you are hurt, neurons specific to pain send a message to the central nervous system where it is passed on to the thalamus – the part of the brain that controls your pain-related responses for self-preservation. Should the injury be fatal, you would then be considered clinically dead, in that your heart has stopped and you are no longer breathing.

However, this is not necessarily the end: "Your brain on the other hand is still working and recent research has shown that during this period, your brain can actually enter a hyper state of perceptual neural activity. Some even believe this could be an explanation of near death experiences. [But] soon your brain will shut down for good and it's what's known as a biological death the last stop on the slasher train."