Excitation Level: Function, Tasks, Role & Diseases

Arousal level corresponds to the activation level of the central nervous system (CNS) and is associated with attention, alertness, and responsiveness. An intermediate level of arousal is considered the basis of highest performance. When negative arousal persists, distress and sometimes phenomena such as burnout syndrome develop.

What is the arousal level?

Arousal level corresponds to the activation level of the central nervous system (CNS) and is associated with attention, alertness, and responsiveness. According to the perceptual chain, the perception of external stimuli results in a reaction to what is perceived in the final step. Thus, responsiveness to the external environment depends significantly on a person’s ability to perceive. With functioning sensory systems, the basis for this ability to react is established. However, people respond more or less well to stimuli from their environment. How well a person can respond to and process stimuli is determined by his or her current level of arousal. This ‘level of arousal’ is the level of a person’s physiological arousal or activation. Activation is in turn the visible readiness to perform a certain action. Arousal is always related to this readiness. The level of activation can range from tension to heightened attention to palpable excitement and the highest possible level of arousal. The extreme states of the level of arousal are rigor mortis and deep sleep or unconsciousness up to coma. In addition to external stimuli and sensory impressions, internal stimuli, such as pain, are also considered triggers of activation. In every external stimulus situation, something changes in the level of arousal. In addition to psychological processes, neuronal processes also play a role in the level of arousal and its level.

Function and task

The so-called arousal is known as a term of psychology and neurology and describes the level of CNS activation. Attention and alertness characterize arousal, as does the resulting responsiveness. The lowest level of arousal exists during sleep. In contrast, when sensory cells transmit pain or related arousal states to the central nervous system, the highest level sometimes exists. Emotions such as anger, fear, and at times sexual desire also increase the level of arousal in the central nervous system. Arousal itself does not have an emotion component, but a biophysiologically measurable quantity in the EEG, which manifests itself in different frequencies with more or less small spikes. The voltage detectable in the EEG and its frequency determine the level of arousal. To trigger arousal, sensory impulses are always necessary, which act on certain parts of the brainstem, triggering stimulation of the cerebral cortex and stimulating the release of the stress hormone adrenaline. From the formatio reticularis, the level of arousal influences the entire organism, the autonomic nervous system and thus also the metabolism. A strong level of arousal causes general alertness and readiness to react. A person with a high level of arousal is particularly susceptible to external stimuli of danger. The readiness to react is increased by the stress hormone adrenaline, which shuts out pain and shuts down all thought processes. This enables the person to flee quickly and to fight enemies with an equally high level of reactivity. The relationship between arousal levels and performance is better understood by the Yerkes-Dodson law of 1908. A person can perform difficult tasks well up to a certain level of arousal. However, when arousal rises above this level, overall performance declines. If it continues to rise, easy tasks become unsolvable and the person is capable of little more. A certain level of arousal, on the other hand, is necessary to be able to perform at all. People achieve the highest performance at a medium arousal level, at the so-called eustress. Above this level, fatigue, exhaustion, or a breakdown can occur.

Diseases and ailments

Stressors cause arousal levels to rise. While some stressors are rated as positive, other stressors are associated exclusively with negative ratings. Persistent arousal due to negative stressors is called distress in medical practice and can promote various medical conditions.Negative are all stimuli that a person evaluates as unpleasant, as threatening or as overstraining. A negative evaluation of stress occurs only after frequent occurrence and the abandonment of a physical compensation. Negative effects are also caused by stressors whose stress cannot be coped with situationally. This is the case, for example, with stressors such as a divorce, an illness or even the death of family members and own illnesses. If the situation of negative arousal cannot be resolved, a strategy for coping must be conveyed to the patients. Since an arousal inform of distress results in a negative tension of the entire body and releases neurotransmitters or hormones such as the stress hormones adrenaline and noradrenaline, persistent distress often permanently changes something in the organism. The attention of the affected person declines. The same applies to their performance, which automatically drops when arousal exceeds the level of eustress. A long-term effect of distress without suitable coping strategies can promote clinical pictures such as the burnout syndrome. The burnout syndrome corresponds to a state of emotional exhaustion that is accompanied by permanently reduced performance and thus leads to ever greater exhaustion. A phase of idealistic enthusiasm is often followed by frustrating events that ultimately lead to disillusionment or even apathy. In addition to burnout, a type of depression, the type of arousal described can trigger psychosomatic illnesses such as addiction or aggression.