When night terrors appear, they show through violent movements and lack of knowledge about their location. Most commonly though, night terrors are characterized by rapidly sitting up, screaming, thrashing, sweating, and staring wide eyed at everything. People also will move from the bed, stay asleep and be lethargic, or crying without pause. In adults, aggressive behavior is far more common. Sleep terrors differ from nightmares in that the dreamer of a nightmare wakes up from the dream and may remember details, but a person who has a sleep terror episode remains asleep. Children usually don't remember anything about their sleep terrors in the morning. Adults may recall a dream fragment they had during the sleep terrors. Also, nightmares generally occur in the last half of the night, while sleep terrors occur in the first half of the night. Children generally scream or thrash in bed. When this occurs the part of the brain that are affected include:
- Nerve-signaling chemicals called neurotransmitters control whether we are asleep or awake by acting on different groups of nerve cells, or neurons, in the brain. Neurons in the brain stem, which connects the brain with the spinal cord, produce neurotransmitters such as serotonin and norepinephrine that keep some parts of the brain active while we are awake. Other neurons at the base of the brain begin signaling when we fall asleep. These neurons appear to "switch off" the signals that keep us awake. Research also suggests that a chemical called adenosine builds up in our blood while we are awake and causes drowsiness. This chemical gradually breaks down while we sleep.
- The lower brain (brain stem) causes REM sleep.
- Functions of the Brain Stem: Maintaining homeostasis by controlling autonomic functions (including blood pressure, breathing, digestion, heart rate, perspiration, and temp), alertness, sleep, balance, startle response.
- Pons: regulates breathing, taste, and autonomic functions.
- Middle brain adds emotion: Contains the limbic system that controls emotional responses and cravings. The Amygdala is an organ in the Limbic System that is active during sleep.
- Functions of Amygdala: Fear processing, emotion processing, learning, flight-or-flight, and reward processing.
- The Amygdala is also called the “seat of fear” because it maintains the flight-or-flight response.
- The most prominent emotional themes in dreams are fear, anxiety, anger, and confusion; providing support for the amygdala’s role in the brain while dreaming.
- The higher brain makes sense of it; the prefrontal cortex that generates language, logic, and critical thinking is turned off while we are asleep. This explains why our brain has irrational fears of goblins, etc. Some critical thinking still occurs in dreams which explains how we are able to “work around” the weird and bizarre events in dreams.