Automatic behavior occurs when the body seemingly has a mind of its own. In such cases, an individual engages in behavior that is out of his or her control. This behavior might include involuntary body movements or unwilling verbal utterances. Several medical conditions manifest with automatic behavior, including epilepsy, hypoglycemia, and some sleep disorders.
In many cases, automatic behavior may occur when the individual is in an altered state of consciousness. For example, individuals with a severe lack of sleep have been observed to exhibit automatic behavior when they are in a semi-conscious state. Demonstrated actions might encompass sleeptalking, sleepwalking, and in the most extreme cases, even demonstrating violent or murderous behavior: homicidal somnambulism. Some individuals accused of crimes have even used automatism as a defense, claiming that criminal actions were not under conscious control. The lack of memory recall individuals sometimes experience supports the notion that the behavior derives from another level of consciousness.
Other disorders may have components of automatic behavior. Due to faulty nerve connections, epileptics may experience seizures or other forms of uncontrolled movements such as chewing or swallowing. Involuntary body ticks or unwanted verbal statements also characterize a disorder known as Tourette's Syndrome. Further, some forms of schizophrenia include catatonic states in which an individual’s level of movement and awareness is severely limited, and another prolonged psychological state of automatic behavior — dissociatve fugue — occurs when an individual unconsciously assumes another life and identity for a period of time. In addition, delirium might occur when an individual’s blood sugar levels drop drastically, sending them into a semi-comatose state.
On a more conventional level, even reflexive actions may be viewed as a type of automatic behavior, since they are facilitated instinctively. Another relatively harmless automatic behavioral form is automatic writing, an ability some individuals have to physically map their brain’s subconscious thought processes via automatic movements of the hand. As for harmful types of automatism, they may be somewhat controlled through medication such as anticonvulsants.
Misfirings in the brain’s neural networks may underpin automatic behavior. Electroencephalogram (EEG) readings of individuals routinely show abnormalities in brain wave patterns. In certain cases, these abnormalities are brought about when an individual rapidly switches from a state of deep sleep or unconsciousness into an alert state without easing through the mid-states that are characteristic of rapid eye movement (REM) sleep. The sleep disorder narcolepsy has the opposite effect, where an individual will rapidly advance from an alert state into deep sleep.