Arousal

Structures of the brainstem, the origin of the arousal system, viewed along the sagittal plane

Wakefulness is regulated by the ascending reticular activating system, which is composed of five major neurotransmitter systems – the acetylcholine, norepinephrine, dopamine, histamine, and serotonin systems – that originate in the brainstem and form connections which extend throughout the cerebral cortex.[1][2][3] When stimulated, these systems produce cortical activity and alertness.[1][2]

The noradrenergic system is a bundle of axons that originate in the locus coeruleus and ascends up into the neocortex, limbic system, and basal forebrain. Most of the neurons are projected to the posterior cortex which is important with sensory information, and alertness. The activation of the locus coeruleus and release of norepinephrine causes wakefulness and increases vigilance. The neurons that project into the basal forebrain impact cholinergic neurons that results in a flood of acetylcholine into the cerebral cortex.

The acetylcholinergic system has its neurons located in the pons and in the basal forebrain. Stimulation of these neurons result in cortical activity, shown from EEG records, and alertness. All of the other four neurotransmitters play a role in activating the acetylcholine neurons.

Another arousal system, the dopaminergic system, releases dopamine produced by the substantia nigra. The neurons arise in the ventral tegmental area in the midbrain, and projects to the nucleus accumbens, the striatum forebrain, limbic system, and prefrontal cortex. The limbic system is important for control of mood, and the nucleus accumbens signal excitement and arousal. The path terminating in the prefrontal cortex is important in regulating motor movements, especially reward oriented movements.

The serotonergic system has almost all of its serotonergic neurons originating in the raphe nuclei. This system projects to the limbic system and the prefrontal cortex. Stimulation of these axons and release of serotonin causes cortical arousal and impacts locomotion and mood.

The neurons of the histaminergic system are in the tuberomammillary nucleus of the hypothalamus. These neurons send pathways to the cerebral cortex, thalamus, and the basal forebrain, where they stimulate the release of acetylcholine into the cerebral cortex.

All of these systems are linked and show similar redundancy. The pathways described are ascending pathways, but there also arousal pathways that descend. One example is the ventrolateral preoptic area, which release GABA reuptake inhibitors, which interrupt wakefulness and arousal. Neurotransmitters of the arousal system, such as acetylcholine and norepinephrine, work to inhibit the ventrolateral preoptic area.

Mental state in terms of challenge level and skill level, according to Csikszentmihalyi's flow model.[4](Click on a fragment of the image to go to the appropriate article)

Arousal is important in regulating consciousness, attention, and information processing. It is crucial for motivating certain behaviors, such as mobility, the pursuit of nutrition, the fight-or-flight response and sexual activity (see Masters and Johnson's human sexual response cycle, where it is known as the arousal phase). Arousal is also an essential element in many influential theories of emotion, such as the James–Lange theory of emotion or the Circumplex Model. According to Hans Eysenck, differences in baseline arousal level lead people to be either extraverts or introverts. Later research suggests that extroverts and introverts likely have different arousability. Their baseline arousal level is the same, but the response to stimulation is different.[5]

The Yerkes–Dodson law states that there is a relationship between arousal and task performance, essentially arguing that there is an optimal level of arousal for performance, and too little or too much arousal can adversely affect task performance. One interpretation of the Yerkes–Dodson law is the Easterbrook cue-utilisation theory. It predicted that high levels of arousal will lead to attention narrowing, during which the range of cues from the stimulus and the environment decreases.[6] According to this hypothesis, attention will be focused primarily on the arousing details (cues) of the stimulus, so that information central to the source of the emotional arousal will be encoded while peripheral details will not.[7]

In positive psychology, arousal is described as a response to a difficult challenge for which the subject has moderate skills.[4]

Arousal is involved in the detection, retention, and retrieval of information in the memory process. Emotionally arousing information can lead to better memory encoding, therefore influencing better retention and retrieval of information. Arousal is related to selective attention during the encoding process by showing that people are more subject to encode arousing information than neutral information.[7] The selectivity of encoding arousing stimuli produces better long-term memory results than the encoding of neutral stimuli.[21] In other words, the retention and accumulation of information is strengthened when exposed to arousing events or information. Arousing information is also retrieved or remembered more vividly and accurately.[22]

Although arousal improves memory under most circumstances, there are some considerations. Arousal at learning is associated more with long-term recall and retrieval of information than short-term recall of information. For example, one study found that people could remember arousing words better after one week of learning them than merely two minutes after learning them.[23] Another study found that arousal affects the memory of people in different ways. Eysenck found an association between memory and the arousal of introverts versus extroverts. Higher levels of arousal increased the number of words retrieved by extroverts and decreased the number of words retrieved by introverts.[23]

A person's level of arousal when introduced to stimuli can be indicative of his or her preferences. One study found that familiar stimuli are often preferred to unfamiliar stimuli. The findings suggested that the exposure to unfamiliar stimuli was correlated to avoidance behaviors. The unfamiliar stimuli may lead to increased arousal and increased avoidance behaviors.[24]

On the contrary, increased arousal can increase approach behaviors as well. People are said to make decisions based on their emotional states. They choose specific options that lead to more favorable emotional states.[25] When a person is aroused, he or she may find a wider range of events appealing[26] and view decisions as more salient, specifically influencing approach-avoidance conflict.[25] The state of arousal might lead a person to view a decision more positively than he or she would have in a less aroused state.

The reversal theory accounts for the preference of either high or low arousal in different situations. Both forms of arousal can be pleasant or unpleasant, depending on a person's moods and goals at a specific time.[27] Wundt's and Berlyne's hedonic curve differ from this theory. Both theorists explain a person's arousal potential in terms of his or her hedonic tone. These individual differences in arousal demonstrate Eysenck's theory that extroverts prefer increased stimulation and arousal, whereas introverts prefer lower stimulation and arousal.[28]

Altered experiences of arousal are associated with both anxiety and depression.

Depression can influence a person's level of arousal by interfering with the right hemisphere's functioning. Arousal in women has been shown to be slowed in the left visual field due to depression, indicating the influence of the right hemisphere.[29]

Arousal and anxiety have a different relationship than arousal and depression. People with anxiety disorders tend to have abnormal and amplified perceptions of arousal. The distorted perceptions of arousal then create fear and distorted perceptions of the self. For example, a person may believe that he or she will get sick from being so nervous about taking an exam. The fear of the arousal of nervousness and how people will perceive this arousal will then contribute to levels of anxiety.[30]

This is caused by withdrawal from alcohol or barbiturates, acute encephalitis, head trauma resulting in coma, partial seizures in epilepsy, metabolic disorders of electrolyte imbalance, intra-cranial space-occupying lesions, Alzheimer's disease, rabies, hemispheric lesions in stroke and multiple sclerosis.[31]

Anatomically this is a disorder of the limbic system, hypothalamus, temporal lobes, amygdala and frontal lobes.[31] It is not to be confused with mania.

The effects of physiological arousal on cognition cause individuals to be active, attentive, or excited. The term "physiological" refers to physiology and concerns the normal functioning of an organism. Physiological arousal refers to features of arousal reflected by physiological reactions, such as escalations in blood pressure and rate of respiration and lessened activity of the gastrointestinal system. These terms are what allow for the effects physiological arousal has on cognition itself.[32]

Cognition is internal mental representations best characterized as thoughts and ideas- resulting from and involved in multiple mental processes and operations including perception, reasoning, memory, intuition, judgement and decision making. While cognition is not directly observable, it is still amenable to study using the scientific method. Cognition is also something that plays a fundamental role in determining behavior. Goes into explaining cognitive functions and how they are internal and inferred from behavior using measure like accuracy in performing a task like recalling a list of words of the time taken to find some word on a page of text. The study of cognitive functions derive from the information processing approach[33] which argues that these functions involve operations occurring at various processing stages is typically based on a model of cognitive function of interest.

Physiological comes from physiology which is the study of the functioning of living organisms, animal or plant, and of the functioning of their constituent tissues or cells. This word was first used by the Greeks to describe a philosophical inquiry into the nature of things. The use of the term with specific reference to vital activities of healthy humans, which began in the 16th century, also applicable to many current aspects of physiology. Physiological responses to fight or flight: When the body is initially challenged by a stressor it responds with physiological activation (also known as arousal) of a defense system to deal with the immediate stressor. "If a stimulus is perceived as a threat, a more intense and prolonged discharge of the locus ceruleus which is the major nor adrenergic nucleus of the brain, giving rise to fibers innervating extensive areas throughout the neuraxis. Also referred as the Neuroaxis, is the axis in the central nervous system. activates the sympathetic division of the autonomic nervous system. (Thase & Howland 1995)" (psychologistworld.org, n.d.)[34] The activation of the sympathetic nervous system leads to the release of non-epinephrine from nerve endings acting on the heart, blood vessels, respiratory centers, and other sites. The ensuing physiological changes constitute a major part of the acute stress response. Which can often lead to as the fight or flight response. Anticipated behaviors are actions that are foreseen or predicted to happen in a specific situation due to different environmental factors. Furthermore, they are decided by one's past experiences and knowledge.

Anticipated behaviors examples

• Someone sitting in the same seat every day during class
• Someone reaching their hand out towards you would indicate they are wanting to shake hands
• While driving a car you would anticipate people braking therefore you would brake as well
• When a loud unexpected noise is created you are startled and flinch
• When a person sneezes you say "bless you"

A real-life example of cognition is used whenever decision making is involved; for example, a real-life scenario of a cognitive decision would be when a traffic light is changing from green to yellow. One would either make a cognitive decision to run through the yellow light in hopes you could clear the intersection before the light turned red. However, one could make a different cognitive decision to stop when they see the yellow light to not run the light before it turned red.

A real-life example of the effects of physiological arousal on cognition is when you're walking through the woods and you notice a rattlesnake in front of the walkway on the ground. You would feel alarmed and scared (physiological arousal). Your past experience and knowledge of poisonous snakes and dangerous predators provides the (cognition) of the situation. Based on your analysis of your position you label your arousal as fear. Fear is explained to be an emotion that one might expect with alarm, it is also known as something to be afraid of or the feelings of apprehensiveness. Fear works when one senses danger, the brain reacts instantly, sending signals that activate the nervous system. This causes physical responses, such as a faster heartbeat, rapid breathing, and an increase in blood pressure. Blood pumps to muscle groups to prepare the body for physical action like running or fighting. Skin sweats to keep the body cool. Some people might notice sensations in the stomach, head, chest, legs, or hands. These physical sensations of fear can be mild or strong. A study done by Joan Vickers and Mark Williams[35] analyzed how a group of elite biathlon shooters handled an experimental task. The goal was to determine why there might be a failure to perform in high pressure situations. Difficulties come about when trying to test performance pressure, physiological workload, anxiety, and visual attention in a controlled setting. Which is why they decided to test these elite biathlon shooters, due to the easy ability to stimulate the controlled experiment. In the low pressure stimulation the subjects were only told that the purpose of the test was to simply provide feedback and the fixation on the target at different power output levels. In the high pressure situation the shorter were told that the national team coach was going to observe the shooters, and their shooting percentages would be used to make the national team selections. Both groups were told that prizes would be rewarded to the most accurate shooters. To test physiological arousal that was being used, Vickers and Williams measured each shooter's heart rate as well as the perceived exertion. Trying to determine if the failure to perform to whatever level of skill or ability the person has at the time, also known as choking; was indeed a factor in this test. Physiological arousal was measured and recorded through the athlete's heart rate and rate of perceived exertion. The findings showed that the biathletes developed the ability to decelerate their heart rate just before they shoot, most only shoot when HR is 80% or lower. Whereas the test was designed for shots to be taken with a heart rate 100% or above. The expectations were for the low-pressure and high-pressure groups to be more prone to choking compared to those who were able to maintain their heart rates. The findings showed exactly what was expected, the only exception was that the pressure applied did not necessarily have much of an effect. While it was clear that high pressure stimulations did appear far more anxious than those of low-pressure stimulations.

Problem solving is the cognitive process that someone uses to achieve a goal whenever a solution cannot be determined by others.

For example, you are with your buddies on a trip and get a flat tire. Everyone looks around nervously because nobody knows how to change a flat. But then you remember that you took an automotive class in college where you learned to change flat tires. You change the tire and solve the issue with your cognitive problem solving. Cognitively, the utilization of logical analysis and problem solving has been associated with higher levels of life satisfaction, better health, and lower depression in caregivers. A realistic appraisal and acceptance of the difficult situation is healthy and allows the caregiver to live his or her own life while accommodating the needs of the recipient. Less effective cognitive coping styles include avoidant-evasive, regressive, and an increased use of wishfulness and fantasizing by the caregiver, all of which have been related to higher levels of care burden (Hayley et al., 1987; Quayhagen & Quayhagen, 1988).

Cognitive appraisal is the stress perceived as imbalance between demands place on the individual and the individual and the individual's resources to cope. Lazarus argued that the experience of stress differs significantly between individuals depending on how they interpret an event and the outcome of a specific sequence of thinking patterns called appraisals.

It also refers to the personal interpretation of a situation that ultimately influences the extent to which the situation is perceived as stressful, process of assessing whether a situation or event threatens our well-being, whether there are sufficient personal resources available for coping with the demand of the situation of whether our strategy for dealing with the situation is effective.

The three parts that it can be divided into are primary appraisal, secondary appraisal, and reappraisal. Primary Appraisal is an assessment of how significant an event is for a person, including whether it is a threat or opportunity, also including that no heightened physiological arousal occurs it means no stress will either. Secondary Appraisal considers one's ability to cope or take advantage of the situation. Cognitive Appraisal is a personal interpretation of a situation and possible reactions to it.

Their secondary appraisal determines what the person will do, and involves their perception of their options and resources.

These appraisals can be accurate or inaccurate, and helping a person arrive at more apt appraisals is a goal of some modes of cognitive behavioral therapy, This is a psychosocial intervention that is the most widely used evidence based practice for improving mental health guided by empirical research cognitive behavioral therapy focuses on the development of personal coping strategies that target solving current problems and changing unhelpful patterns in cognition, behaviors, and emotional regulation. Also known as regulation of emotion; is the ability to respond to the ongoing demands of experience with the range of emotions in a manner that is socially tolerable and sufficiently flexible to permit spontaneous reactions as well as the ability to delay spontaneous reactions as needed. It can also be defined as Extrinsic and Intrinsic processes responsible for monitoring, evaluating, and modifying emotional reactions. Emotional self-regulation belongs to the broader set of emotion-regulation processes, which includes the regulations of one's own feelings and the regulations of other people's feelings.

Look up arousal in Wiktionary, the free dictionary.

• Low arousal approach
• Low arousal theory
• Reversal theory