Brain Structures and Functions Associated with Motivation

Several structures of the brain influence the initiation and maintenance of the motivation required for engaging in healthy eating (Deckers, 2010). Human food consumption implicates evolutionary factors such as the pleasurable reinforcement of endorphins and serotonin activity that produce a sense of fullness and well-being after eating (Placidi et al., 2004). To deny some of these reinforcing experiences, at least initially, there is often difficulty in maintaining changes in the diet. Many intrinsic and extrinsic factors influence the implementation of new and specific behavior such as maintaining a healthy diet (Deckers, 2010). Ultimately, success has its roots in the individual's capacity to maintain continual motivation to engage in the chosen behavior. Many brain structures contribute to that capacity.

Intrinsic Factors Motivating Healthy Eating

Brain Structures Involved in Motivation

Maintaining motivation for healthy eating partly depends on a set of structures of the limbic system that includes the hypothalamus, the hippocampus, and the amygdala (Wickens, 2005). These structures affect the formation of new memories and regulate emotions that contribute to maintaining a positive attitude about diet changes (Wickens, 2005). The limbic system is connected to reward and motivation, which is a necessary factor in maintaining a new diet and feeling a sense of reward in its accomplishment (Adcock et al., 2006). Adcock et al. (2006) found that reward strengthened motivation and helped new memory formation when dopamine is released in the hippocampus. According to DeVietti and Kirkpatrick (1977), the stimulation of the amygdala was critical in recalling new learning and retaining new habits, such as engaging in healthy eating. The highly developed human prefrontal cortex exerts control over impulsive behavior and the ability to make good judgments regarding food choices (Spinks, n.d.).

Additional areas of the brain include the mesolimbic opioid and dopamine circuits implicated in abnormally increased appetite for and consumption of food (Placidi et al., 2004). Increased appetite is often associated with injury or dysfunction in the hypothalamus (Placidi et al., 2004). According to Deckers (2010), within brain structures, neurons send, receive, and transmit information through electrical and chemical stimulation. One of the chemical transmitters is dopamine, which is associated with reward and pleasurable sensations, and is implicated in the satisfaction experienced by maintaining a healthy diet (Wickens, 2010).

Evolutionary Factors

One of the first challenges of eating healthy is the intrinsic and sometimes indiscriminate need to eat (Deckers, 2010). When individuals are hungry, there is a natural tendency to eat whatever is most readily available (Deckers, 2010). The hypothalamus regulates the evolutionary response to hunger and thirst, and can signal hunger in response to radical changes in the diet (Wickens, 2005). According to Deckers (2010), the dopamine system powerfully affects the motivational aspects of thinking. From an evolutionary standpoint, the dopamine system functions to promote pleasure for survival activities like eating, drinking, and sex (Deckers, 2010). Dopamine is pleasure inducing, so people are motivated toward behaviors that cause dopamine to release into the system (Deckers, 2010). When embarking on a new eating regime, there may be some challenge to this system, as some of the pleasurable sensations of eating are temporarily withdrawn or modified.

Genetic Factors

Genetic and cultural factors may influence the ability to engage in healthy eating. These may include biological predispositions including allergies, food intolerances, and a predisposition to cultural flavors (Wickens, 2007). According to Hotelling and Liston (2004), disordered eating is a hereditary factor that can exert influence on maintaining a healthy diet, and is often a hereditary factor just as alcoholism, depression, and substance abuse.

The frontal lobes function as the control center of our personality and enable the distinction between appropriate and inappropriate food choices (Deckers, 2010). In the case of culturally acceptable choices, the individual may need to reprogram ideas of acceptable foods and habits (Lockyear, 2004). Additionally, the inherited quality of general intelligence, regulated by the prefrontal cortex, is involved in making more intelligent lifestyle and eating choices (Deckers, 2010).

In the central nervous system, differences in genetic makeup affect perception of taste, degree of satiation, and other considerations that affect food intake (Wickens, 2007). Perceptions are regulated by several brain structures such as the prefrontal cortex, but are also affected by personal preference and experience, which involves brain structures involved in memory (Deckers, 2010). Other psychological factors that may have some genetic basis include the inability to cope with stress, unhappiness, and boredom (Deckers, 2010, Wickens, 2007). These emotions can challenge the motivation required to maintain healthy eating (Deckers, 2010).

Serotonin System

Individuals with more serotonin in the synapse usually eat less and can be more discerning in food choices (Placidi et al., 2004). This may be because the serotonin in the neural system provides a sense of well-being without needing food to provide this sense (Placidi et al., 2004). Less serotonin in the synapse can cause depression, which can cause weight gain and less desire to maintain a healthy diet. According to Placidi et al. (2004), changes in serotonin levels are directly linked to dieting and binge eating. The more serotonin available in the synapse, the more sated the individual remains, and the more discerning the appetite (Placidi et al., 2004).

Extrinsic Factors Motivating Healthy Eating

Social Encouragement and Other Environmental Conditions

Social expectation and perception is a heavy factor in an individual's desire to maintain a diet that includes healthy food choices (Deckers, 2010). Various views and opinions can alter the perception of a healthy diet (Lockyear, 2004). The opinions of one's close social circle will either help or hinder motivation in maintaining healthy options (Lockyear, 2004). Social acceptance is a known psychological need (Deckers, 2010), and food choices can isolate or associate individuals in some social circumstances. Both isolation and association are effective extrinsic motivators that may affect food choices (Deckers, 2010). Another extrinsic motivator for engaging in healthy eating may involve a doctor's warning that without an alternative diet, the individual's health may be in jeopardy.

Positive Reinforcement

Positive reinforcement from family and friends accounts for a better prognosis for creating and maintaining new diets and healthy lifestyles (Eat Out, 2010). Individuals whose families eat according to cultural norms may have difficulty convincing the family to be a positive influence, especially if the diet is not consistent with cultural traditional (Lockyear, 2004). Motivation may be enhanced or decreased by the effects of the family or friend's perspective of the new diet. Alternately, the family and friends may already have healthy diets and the individual may be coerced into engaging in behavior similar to family and friends. Some of these extrinsic motivations may become intrinsic when the individual experiences the sense of reward and accomplishment from maintaining the new healthy diet (Deckers, 2010).

***

Intrinsic and extrinsic motivating factors are influenced by a variety of biological states, brain structures and their efficient functioning, which consequently influences the decision-making ability of the individual (Wickens, 2007). Some motivating factors are more influential than others are, although the individual's biological state is most significant. Motivating factors, while highly influential, must be processed according to the capable functioning of the brain and nervous system (Wickens, 2007). These key components play a significant role in the individual's psychological state and perceptive abilities (Wickens, 2005). Additionally, the brain and nervous system affect how the individual processes the motivating factors (Wickens, 2005). Whatever the motivating elements, the biological state will ultimately determine the individual's ability to mobilize the motivation necessary to engage in initiating and maintaining a healthy diet.

References

Adcock, R. A., Thangavel, A., Whitfield-Gabrieli, S., Knutson, B., & Gabrieli, J. D. (2006). Reward-Motivated Learning: Mesolimbic Activation Precedes Memory Formation. Neuron, 50(3), 507-517. doi: 10.1016/j.neuron.2006.03.036

Deckers, L. (2010). Motivation: Biological, Psychological, and Environmental (3rd ed.). Boston: Pearson/Allyn & Bacon.

DeVietti, T. L., & Kirkpatrick, B. R. (1977). Stimulation of specific regions of brain in rats modifies retention for newly acquired and old habits. Journal of Comparative and Physiological Psychology, 91(3), 662-673. doi: 10.1037/h0077343

Eat Out. (2010, July 8). Family and friends have more influence on diet than the government, online healthy living survey reveals - Eat Out Magazine. Latest restaurant, pub, bar and hotel news from Eat Out magazine. Retrieved November 17, 2010, from http://www.eatoutmagazine.co.uk/online_article/Family-and-friends-have-more- influence-on-diet-than-the-government,--online-healthy-living-survey-reveals/11288

Hotelling, K. & Liston, L. K. Guidelines for the outpatient management of individuals with eating disorders in the university setting. (2004). Northern Illinois University. Retrieved November 16, 2010, from http://www.aucccd.org/img/pdfs/eating_disorder_manual.pdf

Lockyear, P. L. (2004). Cultural Differences in Diet and Heart Health Among Women: Culture and Diet. Medscape Today. Retrieved November 17, 2010, from http://www.medscape.com/viewarticle/490343_2

Placidi, R. J., Chandler, P. C., Oswald, K. D., Maldonado, C., Wauford, P. K., & Boggiano, M. M. (2004). Stress and hunger alter the anorectic efficacy of fluoxetine in binge-eating rats with a history of caloric restriction. International Journal of Eating Disorders, 36(3), 328-341. doi: 10.1002/eat.20044

Spinks, S. (n.d.). Frontline: inside the teenage brain: work in progress: adolescent brains are a work in progress | PBS. PBS: Public Broadcasting Service. Retrieved November 11, 2010, from

http://www.pbs.org/wgbh/pages/frontline/shows/teenbrain/work/adolescent.html

Wickens, A.P. (2005). Foundations of Biopsychology (2nd ed.). New York: Pearson/Prentice Hall.