With October right around the corner, it is the time of pumpkin spice flavored everything, leaves changing colors, sweaters, and of course scary movies. But what is it that makes these movies scary? Between the music, the lighting, and of course the mystery of the person behind the mask we are placed into a new feeling…fear! We have all felt it before. The hair on the back of your neck and arms standing up, your heart racing, pupils wide, that feeling of being on the edge of your seat. So, what is it neurologically that happens in our bodies to make all these responses occur? Here is a list below of the major players:
- Adrenal Gland– Part of your endocrine system. It produces many kinds of hormones that activate and regulate anxious, fearful, and stress responses. As the name suggests, it is the brain's adrenaline factory.
- Amygdala– The brain's emotional organizational center. The amygdala separates your emotional responses into threatening or non-threatening camps and is the storehouse of fearful memories and associations.
- Hippocampus– A primary brain structure for memory. The hippocampus both files away and recalls conscious memories and is one of the first-responders to give context and meaning to sensations and stimuli.
- Hypothalamus– This tiny structure is the seed of your "fight, flight, or freeze" response.
- Pituitary Gland– Another endocrine structure. Together with the hypothalamus and adrenal gland, it forms a feedback system that controls stress reactions, mood, and emotion.
- Sensory Cortex– The brain structure responsible for collecting contextualized sensory information.
- Thalamus– A junction box for sensory information. The thalamus reroutes specific sensory information to other parts of the brain.
- ACTH, Cortisol, Oxytocin, Epinephrine (Adrenaline), and Norepinephrine– A sampling of the over 30 hormones and chemicals released during "flight, fight, or freeze" responses. They are released by both your adrenal (bloodstream) and autonomic nervous systems.
First, you see something that you perceive scary or suspenseful. The visual information you just took in was taken from your eyes to your thalamus and was next relayed to your amygdala. This information was also sent to your visual cortex to compare if this sight you just observed is potentially threatening. That goblin or monster you just observed, was interpreted as a threat which lead to your autonomic nervous system to bias your “fight or flight response” from your sympathetic system, leading to an increase in hear rate, blood pressure, and dilation of your pupils. This activation of your sympathetic nervous system also leads to stimulation of your piloerector muscles, causing them to contract and allow the hair on the back of your neck and arms to stand.
But now what about the memory of those events? How are we able to classify something as scary, think back to it and still have these similar responses? This is because this information is stored in your lateral amygdala with the help of the neurotransmitter glutamate. The amygdala, in combination with the hippocampus, helps to store the event by using neuroplasticity.
As you can tell there is a lot of information and adaptation that occurs with the sights, smells and sounds of a scary or suspenseful event. This will give you something to think about the next haunted hayride or haunted house you visit.