Arousal in the context of Dopamine

An altered level of consciousness is any measure of arousal other than normal. Level of consciousness (LOC) is a measurement of a person's arousability and responsiveness to stimuli from the environment. A mildly depressed level of consciousness or alertness may be classed as lethargy; someone in this state can be aroused with little difficulty. People who are obtunded have a more depressed level of consciousness and cannot be fully aroused. Those who are not able to be aroused from a sleep-like state are said to be stuporous. Coma is the inability to make any purposeful response. Scales such as the Glasgow coma scale have been designed to measure the level of consciousness.

An altered level of consciousness can result from a variety of factors, including alterations in the chemical environment of the brain (e.g. exposure to poisons or intoxicants), insufficient oxygen or blood flow in the brain, and excessive pressure within the skull. Prolonged unconsciousness is understood to be a sign of a medical emergency. A deficit in the level of consciousness suggests that both of the cerebral hemispheres or the reticular activating system have been injured. A decreased level of consciousness correlates to increased morbidity (sickness) and mortality (death). Thus it is a valuable measure of a patient's medical and neurological status. In fact, some sources consider level of consciousness to be one of the vital signs.

An adventure is an exciting experience or undertaking that is typically bold, sometimes risky. Adventures may be activities with danger such as traveling, exploring, skydiving, mountain climbing, scuba diving, river rafting, or other extreme sports. Adventures are often undertaken to create psychological arousal or in order to achieve a greater goal, such as the pursuit of knowledge that can only be obtained by such activities.

Electrodermal activity (EDA) is the property of the human body that causes continuous variation in the electrical characteristics of the skin. Historically, EDA has also been known as skin conductance, galvanic skin response (GSR), electrodermal response (EDR), psychogalvanic reflex (PGR), skin conductance response (SCR), sympathetic skin response (SSR) and skin conductance level (SCL). The long history of research into the active and passive electrical properties of the skin by a variety of disciplines has resulted in an excess of names, now standardized to electrodermal activity (EDA).

The traditional theory of EDA holds that skin resistance varies with the state of sweat glands in the skin. Sweating is controlled by the sympathetic nervous system, and skin conductance is an indication of psychological or physiological arousal. If the sympathetic branch of the autonomic nervous system is highly aroused, then sweat glands activity also increases, which in turn increases skin conductivity. In this way, skin conductivity can be a measure of emotional and sympathetic responses. But the theory associating sweat and EDA was already debated decades ago since individuals without sweat glands have an EDA signal : ""The source of the skin potential is presumed to be the sweat glands and the epidermis, although it is present in subjects with congenital absence of sweat glands ... this is not a test of “sweat” function, it is often included in this category as a measure of sudomotor activity".". This debate is ongoing since more recent technology (see Electrochemical skin conductance) demonstrated a real measure of sweat conductivity with several medical applications. A good way to differentiate both is to look at measures values and type :

Mania (/meɪniːˈə/ MAIN-ee-yah; also known as manic syndrome) is a psychiatric behavioral syndrome defined as a state of abnormally elevated arousal, affect, and energy level. During a manic episode, an individual will experience rapidly changing emotions and moods, highly influenced by surrounding stimuli. Although mania is often conceived of as a "mirror image" to depression, the heightened mood can be dysphoric as well as euphoric. As the mania intensifies, irritability can be more pronounced and result in anxiety or anger.

The symptoms of mania include elevated mood (either euphoric or irritable), flight of ideas, pressure of speech, increased energy, decreased "need" and desire for sleep, and hyperactivity. They are most plainly evident in fully developed hypomanic states, however, in full-blown mania, these symptoms become progressively exacerbated. In severe manic episodes, these symptoms may even be obscured by other signs and symptoms characteristic of psychosis, such as delusions (it may include delusions of grandeur and paranoid delusions), hallucinations, fragmentation of behavior, and catatonia.

Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of psychoactive drugs that increase alertness. They are used for various purposes, such as enhancing attention, motivation, cognition, mood, and physical performance. Some stimulants occur naturally, while others are exclusively synthetic. Common stimulants include caffeine, nicotine, cocaine (including crack cocaine), amphetamine/methamphetamine, methylphenidate, and modafinil. Stimulants may be subject to varying forms of regulation, or outright prohibition, depending on jurisdiction. Most stimulants are highly addictive and damage health when addicted.

Stimulants increase activity in the sympathetic nervous system, either directly or indirectly. Prototypical stimulants increase synaptic concentrations of excitatory neurotransmitters, particularly norepinephrine and dopamine (e.g., methylphenidate). Other stimulants work by binding to the receptors of excitatory neurotransmitters (e.g., nicotine) or by blocking the activity of endogenous agents that promote sleep (e.g., caffeine). Stimulants can affect various functions, including arousal, attention, the reward system, learning, memory, and emotion. Effects range from mild stimulation to euphoria, depending on the specific drug, dose, route of administration, and inter-individual characteristics.

Depressants, also known as central nervous system depressants, or colloquially known as "downers", are a class of psychoactive drugs characterised by decreasing neurotransmission levels, decreasing the electrical activity of brain cells, or reducing arousal or stimulation in various areas of the brain. Commonly used depressants include alcohol, opioids, and benzodiazepines. Some specific depressants influence mood, either positively (e.g., opioids) or negatively (e.g., alcohol), but depressants often have no clear impact on mood (e.g., most anticonvulsants). In contrast, stimulants, or "uppers", increase mental alertness, making stimulants the opposite drug class from depressants. Antidepressants are defined by their effect on mood, not on general brain activity, so they form an orthogonal category of drugs.

Depressants are closely related to sedatives as a category of drugs, with significant overlap. The terms may sometimes be used interchangeably or may be used in somewhat different contexts. Nearly all commonly used depressants are addictive, and use of them carries the risk of death from respiratory depression, especially in opioids.

In psychology, relaxation is the emotional state of low tension, in which there is an absence of arousal, particularly from negative sources such as anger, anxiety, or fear.

Relaxation is a form of mild ecstasy coming from the frontal lobe of the brain in which the backward cortex sends signals to the frontal cortex via a mild sedative. Relaxation can be achieved through meditation, autogenics, breathing exercises, progressive muscle relaxation and other means.

The James–Lange theory (1884) is a hypothesis on the origin and nature of emotions and is one of the earliest theories of emotion within modern psychology. It was developed by philosopher John Dewey and named for two 19th-century scholars, William James and Carl Lange (see modern criticism for more on the theory's origin). The basic premise of the theory is that physiological arousal instigates the experience of emotion. Previously people considered emotions as reactions to some significant events or their features, i.e. events come first, and then there is an emotional response. James-Lange theory proposed that the state of the body can induce emotions or emotional dispositions. In other words, this theory suggests that when we feel teary, it generates a disposition for sad emotions; when our heartbeat is out of normality, it makes us feel anxiety. Instead of feeling an emotion and subsequent physiological (bodily) response, the theory proposes that the physiological change is primary, and emotion is then experienced when the brain reacts to the information received via the body's nervous system. It proposes that each specific category of emotion is attached to a unique and different pattern of physiological arousal and emotional behaviour in reaction due to an exciting stimulus.

The theory has been criticized and modified over the course of time, as one of several competing theories of emotion. Modern theorists have built on its ideas by proposing that the experience of emotion is modulated by both physiological feedback and other information, rather than consisting solely of bodily changes, as James suggested. Psychologist Tim Dalgleish states that most modern affective neuroscientists would support such a viewpoint. In 2002, a research paper on the autonomic nervous system stated that the theory has been "hard to disprove". Despite important critical appraisals, the theory finds support even today: famed consciousness researcher Anil Seth is known for supporting a form of this theory.

An adventure is a novel and exciting undertaking that is typically bold, sometimes risky. Adventures may be activities with danger such as traveling, exploring, skydiving, mountain climbing, scuba diving, river rafting, or other extreme sports. Adventures are often undertaken to create psychological arousal or in order to achieve a greater goal, such as the pursuit of knowledge that can only be obtained by such activities.

Pyromania is an impulse-control disorder in which individuals repeatedly fail to resist impulses to deliberately start fires, to relieve some tension or for instant gratification. The term pyromania comes from the Greek word πῦρ (pyr, 'fire'). Pyromania is distinct from arson, which is the deliberate setting of fires for personal, monetary or political gain. Pyromaniacs start fires to release anxiety and tension, or for arousal. Other impulse-control disorders include kleptomania and intermittent explosive disorder.

There are specific symptoms that separate pyromaniacs from those who start fires for criminal purposes or due to emotional motivations not specifically related to fire. Someone with this disorder deliberately and purposely sets fires on more than one occasion, and before the act of lighting the fire the person usually experiences tension and an emotional buildup. When around fires, a person with pyromania gains intense interest or fascination and may also experience pleasure, gratification or relief. Another long term contributor often linked with pyromania is the buildup of stress. When studying the lifestyle of someone with pyromania, a buildup of stress and emotion is often evident; this is seen in teenagers' attitudes towards friends and family. At times it is difficult to distinguish the difference between pyromania and experimentation in childhood because both involve receiving gratitude from fire.

A vegetative state (VS) or post-coma unresponsiveness (PCU) is a disorder of consciousness in which patients with severe brain damage are in a state of partial arousal rather than true awareness. After four weeks in a vegetative state, the patient is classified as being in a persistent vegetative state (PVS). This diagnosis is classified as a permanent vegetative state some months (three in the US and six in the UK) after a non-traumatic brain injury or one year after a traumatic injury. The term unresponsive wakefulness syndrome may be used alternatively, as "vegetative state" has some negative connotations among the public. It is occasionally also called Apallic syndrome or Apallisches syndrome, borrowings from German, primarily in European or older sources.

Expectancy violations theory (EVT) is a theory of communication that analyzes how individuals respond to unanticipated violations of social norms and expectations. The theory was proposed by Judee K. Burgoon in the late 1970s and continued through the 1980s and 1990s as "nonverbal expectancy violations theory", based on Burgoon's research studying proxemics. Burgoon's work initially analyzed individuals' allowances and expectations of personal distance and how responses to personal distance violations were influenced by the level of liking and relationship to the violators. The theory was later changed to its current name when other researchers began to focus on violations of social behavior expectations beyond nonverbal communication.

This theory sees communication as an exchange of behaviors, where one individual's behavior can be used to violate the expectations of another. Participants in communication will perceive the exchange either positively or negatively, depending upon an existing personal relationship or how favorably the violation is perceived. Violations of expectancies cause arousal and compel the recipient to initiate a series of cognitive appraisals of the violation. The theory predicts that expectancies influence the outcome of the communication interaction as either positive or negative and predicts that positive violations increase the attraction of the violator and negative violations decrease the attraction of the violator.