Motivation and emotion/Book/2017/Norepinephrine and motivation

Overview
Motivation and norepinephrine are linked through the intermediary concept of arousal. Arousal gives behaviour its energy (Landers and Arent, 2010). Norepinephrine (NE) has been implicated in arousal (Southwick, Bremner, Rasmusson, Morgan, Arnsten, & Charney, 1999). Through wide reaching efferent projections from its center of production in the brain, NE effects many areas of the brain that are responsible for arousal. The dysregulation of arousal is linked to a number of disorders including PTSD, insomnia, and depression. Dysregulation of arousal is linked to the dysregulation of the noradrenergic system in the release and reuptake of NE. NE levels can be brought under control using both pharmacological and psychological interventions.

According to Landers and Arent (2010) the term arousal has been used interchangeably with anxiety in some of the literature. These terms will be separated herein and a further distinction will be made between state and trait anxiety. Arousal theories that will be discussed are the Inverted-U hypothesis, Individual Zones of Optimal Functioning, and the Yerkes-Dodson Law.

NE is discussed within the context of these theories to show how the regulation of NE levels can be used to explain the variation of the level of arousal among individuals and within the individual to energise behaviour.

Arousal
Arousal is a bodily activation state that is neither negative or positive (Landers & Arent, 2010). Several theories have been proposed to address how arousal energises behaviour. Before the discovery of an arousal system within the brain, drive theory was used to describe the concept that energised behaviour.

Drive Theory
Landers and Arent (2010) equate drive with arousal. The reason for this definition of drive is because both drive and arousal refer to the intensity dimension of behaviour (Landers and Arent, 2010). Gould, Greenleaf, and Krane (2002) are in agreement that drive is synonymous with arousal. Drive theory postulates that performance is a product of drive and habit strength or P = H x D. Habit strength is the strength of the dominant response (Gould, Greenleaf, & Krane, 2002). When a person is learning a new skill their dominant response is incorrect but as they practice more the dominant response is the right one (Gould, Greenleaf, & Krane, 2002). Therefore, a high level of arousal would be detrimental to a novice learning a new skill but not for a skilled performer as the formula describes (Gould, Greenleaf, & Krane, 2002).

The Inverted-U Hypothesis
The inverted-U hypothesis postulates that as arousal increase so does performance up to a certain point at which time further increases in arousal decreases performance (Landers and Arent, 2010). Yerkes and Dodson first proposed the theory in 1908 (Gould, Greenleaf, & Krane, 2002). Evidence for the inverted U hypothesis was found in a study by Duffy (1932) in which an increase in muscle tension led to poor performance in a muscle activity and that high tension would decrease muscle flexibility. Duffy (1932) determined that a medium level of muscle tension was optimal.

Task Specificity
The Yerkes-Dodson law states that the inverted-U hypothesis is task specific (Landers and Arent, 2010). Gross motor skill tasks require a higher level of arousal compared to fine motor skill tasks (Hebb, 1953). As arousal increases focus narrows to block out task irrelevant cues (Landers and Arent, 2010). As arousal continues to increase focus narrows further blocking out task relevant cues thus decreasing performance (Landers and Arent, 2010).

Individual Zones of Optimal Functioning (IZOF)
The optimal level of arousal differs among individuals (Landers and Arent, 2010). The so called Individualised Zone of Optimal Functioning is a concept used to describe that each person has a zone of optimal functioning that is somewhere between comatose and panicked (Landers and Arent, 2010). The IZOF model cannot be used to make direct inferences to the inverted-U hypothesis because it has only been operationalised with measures of anxiety (Landers and Arent, 2010).

Anxiety
Anxiety is a negative emotional state that has been used synonymously, at times, with arousal. However, arousal is neither positive nor negative (Landers and Arent, 2010). Certainty and uncertainty are the key determinants as to whether a high arousal level is perceived as stress, distress, or anxiety (Landers and Arent, 2010). A high level of uncertainty causes anxiety but even though a low level of uncertainty cause low anxiety it also leaves a person under aroused, which leads to under performance (Landers and Arent, 2010). A major task carried out by sports psychologists is teaching athletes to control their anxiety levels because a high level of arousal does not have to mean a corresponding high level of anxiety (Landers and Arent, 2010). Two types of anxiety have been proposed, state anxiety and trait anxiety.

State Anxiety
State anxiety is an emotional state in which perceived feelings of apprehension and tension are associated with activation or arousal of the autonomic nervous system (Landers and Arent, 2010). State anxiety is specific to a particular task or situation (Landers and Arent, 2010). When state anxiety becomes a generalised to other tasks and situations this is referred to as trait anxiety (Landers and Arent, 2010).

Trait Anxiety
Trait anxiety is an acquired behavioural disposition that predisposes an individual to perceive a wide range of circumstances as threatening and to respond to these with state anxiety reactions (Landers & Arent, 2010).



Norepinephrine
Norepinephrine (NE) found in the central nervous system (CNS) is produced by the locus coeruleus. The majority of cell bodies of noradrenergic nuclei in the central nervous system are found in the locus coeruleus (Southwick et al., 1999). Norepinephrine (NE) is involved in selective attention to meaningful stimuli (Southwick et al., 1999). Stress and fear-related activation of the locus coeruleus increases release of NE in multiple brain regions that deal with the perception, evaluation and response to potentially threatening stimuli (Southwick et al., 1999).

Southwick et al. (1999) claim that the firing rate of locus coeruleus has been associated with the level of alertness. Locus coeruleus neurons are most active during and just before waking and much less active during sleep (Foote, Aston-Jones, & Bloom, 1980). It has been suggested that the locus coeruleus plays an important role in the maintenance of arousal levels in the CNS (Southwick et al., 1999). A higher firing rate is associated with alertness while a low firing rate is associated with drowsiness. Increased activity of the locus coeruleus causes an increases in the release of NE from locus coeruleus efferent projections (Southwick et al., 1999). The increases and decreases in arousal level that coincide with the activity of the locus coeruleus and subsequent increases and decrease in NE levels appear to follow from the same pattern as described by the inverted-U hypothesis. It is reasonable to deduce from the evidence presented that NE levels are at the very least a contributing factor in the arousal theories presented thus far and also in the regulation of anxiety.

Arousal Regulation
Both pharmacological and psychological intervention have been shown to be effective in the regulation of arousal (Williams, 2010; Southwick et al., 1999). Research findings demonstrate that the autonomic nervous system can be controlled voluntarily and that the techniques can be easily taught (Williams, 2010). Pharmacological interventions that target noradrenergic receptors have been shown to both up-regulate and down-regulate arousal levels depending on the receptor targeted (Southwick et al., 1999).

Decreasing Arousal
An over aroused state is counter-productive to performance as shown by the inverted-u hypothesis (Landers and Arent, 2010). An increase in muscular tension can hinder performance and so it is beneficial to learn techniques to decrease the level of arousal (Duffy, 1932). The psychological interventions that will be discussed fall into two distinct categories, muscle-to-mind and mind-to-muscle (Williams, 2010). Muscle-to-mind interventions focus on relieving tension in the muscles which in turn feeds back to the brain, relaxing the mind (Williams, 2010). Mind-to-muscle interventions focus on clearing the mind which in turn relaxes the body (Williams, 2010). For arousal dysregulation disorders such as PTSD and Insomnia pharmacological interventions may be necessary and one such treatment will be discussed (Southwick et al., 1999).

Breathing Exercises
When a person is highly aroused and/or anxious breathing shallows and heart rate increases as a result of the effect of norepinephrine on the heart and lungs due to the activation of the autonomic nervous system (Williams, 2010; Southwick et al., 1999). Breathing exercises that focus on deep, slow, diaphragmatic breathing can both slow the heart rate and lead to a deep state of relaxation (Williams, 2010). Using a 1:2 works to ensure a full breath is inhaled, breathe in to a count of four and out to a count of eight (Williams, 2010). Using a count down from 5 to 1 with each breath and saying to one's self that I am more relaxed now that I am at 5, now that I am at 4, continuing down to 1 leads to a sense of deep relaxation (Williams, 2010).

Progressive Relaxation
Progressive Relaxation entails contracting a specific muscle group for 5-7 seconds before relaxing it and moving onto the next muscle group (Williams, 2010). Contracting the muscle group creates in the person an awareness of how muscle tension feels (Williams, 2010). Likewise relaxing the muscle teaches the person how a relaxed muscle group should feel (Williams, 2010). The intention is that a person should be able to with some automaticity be able to recognise tension in muscles and relax those tensions (Williams, 2010). Progressive relaxation has been shown to be an effective treatment for insomnia (Greeff & Conradie, 1998).

Meditation
Four components are typical of most meditation techniques (Williams, 2010). The four components are a comfortable position, a quite environment, a mental device, and a passive attitude (Williams, 2010). Meditation is used to achieve a sense of deep relaxation, it relaxes the mind and as a result relaxes the body (Benson, 1975).

The relaxation response is a meditative technique developed by Herbert Benson (1975). The relaxation response is devoid of any religious of cultic symbolism or reference (Benson, 1975). The directions for the relaxation response are as follows:


 * 1) Sit in a comfortable position with the eyes closed.
 * 2) Relax the muscles, starting at the top of the head and working down to the toes.
 * 3) Concentrate on each breath, keeping it as natural as possible. On exhalation say the word calm or any other neutral word.
 * 4) When finished, sit quietly with your eyes closed for a few minutes before opening them. Do not stand for several minutes.

Williams (2010) recommends starting with 5 minutes initially and building to 15-20 minutes.

Visualisation
Using visualisation techniques is an effective way to decrease arousal level by visualising being in a relaxing place. A form of visualisation that has been used extensively with European athletes is autogenic training (Williams, 2010). Autogenic Training consists of six stages that typically take several months for a person to become proficient (Williams, 2010). The sensations that autogenic training exercises aim to produce are warmth and heaviness (Williams, 2010).

Clonidine
The work of Southwick et al. (1999) suggests that pharmacological agents that specifically target noradrenergic hyperactivity might be useful in the treatment of PTSD. Clonidine is an α2 adrenergic receptor agonist that has been reported to be helpful in a range of arousal related PTSD symptoms (Southwick et al., 1999).

Increasing Arousal
The Inverted-U hypothesis shows that under arousal leads to poor performance (Arent & Landers, 2003). Likewise, low arousal levels that are apparent in people with depression can be influenced not only by pharmacological means but also through psychological means. Just as there are many techniques to decrease arousal so too there are many to increases arousal levels and they will be discussed next.

Breathing
Controlling the breathing rate works just as well for increasing arousal as it does for decreasing arousal (Williams, 2010).The breathing technique begins with the person first becoming aware of their breathing (Williams, 2010). They are then asked to notice the rhythm of their breathing before being asked to increase the breathing rhythm (Williams, 2010). As the person exhales they should imagine that they are exhaling fatigue and inhaling energy (Williams, 2010).

Energising Imagery
Energising imagery is useful when fatigue has set in or energy is needed to finish a play in sport (Williams, 2010). An example of the use of energising imagery is found in the Australian movie from 1981 called Gallipoli:

Jack: What are your legs?

''Archy Hamilton: Springs. Steel Springs.''

Jack: What are they going to do?

Archy Hamilton: Hurl me down the track.

Jack: How fast can you run?

Archy Hamilton: As fast as a leopard.

Jack: How fast are you going to run?

Archy Hamilton: As fast as a leopard!

Jack: Then let’s see you do it!

Verbal Cues
In sport verbal cues such as go, explode, fire-up can quickly be associated with energy build-up (Williams, 2010). Taking this a step further, Raiport (1988) described a technique used by Eastern European sport psychologist that combined energising cues, images, and breathing. The technique consisted of a series verbal statements coupled with mental imagery and breathing. For example, in the following statement taken from Raiport (1988) the italicised section of the statement is said on the inhalation because this is the point where muscle tension is felt:

“My breathing is becoming cooler” (Repeat 4 times)

Imagine a fresh breeze blowing on your face. Feel the goose bumps appearing on your skin as you begin to shiver slightly.

In this way the verbal cue was used in conjunction with the breathing technique and then the imaging of the cool breeze, goose bumps and shivering to strengthen the effect.

Serotonin and norepinephrine reuptake inhibitors
Serotonin and norepinephrine reuptake inhibitors increase the amount of serotonin and norepinephrine circulating within the central nervous system by blocking the reabsorption of these neurotransmitters. This group of drugs include venlafaxine and duloxetine (http://www.oxfordreference.com/view/10.1093/acref/9780199687817.001.0001/acref-9780199687817-e-11851)

Conclusion
NE affects motivation through its regulation of arousal. Each person has an optimal level of arousal at which they perform best. The optimal level of arousal differs between individuals and within an individual dependent on the task being performed. Arousal level can be regulated using psychological and pharmacological interventions. Based on these assertions a person can regulate their arousal in any situation to energise behaviour to perform at their best.