Motivation and emotion/Book/2019/Dorsolateral prefrontal cortex and long-term goal pursuit

From Wikiversity
Jump to navigation Jump to search
The dorsolateral prefrontal cortex and long-term goal pursuit:
What role does the dorsolateral prefrontal cortex play in pursuing long-term goals?

Overview[edit | edit source]

"FOR THE ONE HUNDREDTH TIME, LIAM - GET UP OFF THE COUCH AND CLEAN YOUR ROOM, YOU SAID YOU WOULD KEEP IT CLEAN!"

Ah. Mum is yelling at me again. I often wonder why I'm so useless. If only there was some way to understand why I can't pursue any long-term goals.

"Sorry mum, I'll make sure to keep it clean".

Long-term goals are a major contributor to our daily functioning. They direct our actions, give us a sense of purpose, and shape our attitudes towards objects, people and circumstances. It is therefore critical we understand the importance in creating and achieving long term goals. Unfortunately it is easier said than done. There are numerous complexities in the cognitive functioning required to achieve long-term goals. This chapter examines:

  1. The role of the dorsolateral prefrontal cortex
  2. Typical functioning of the human brain
  3. How to achieve long-term goal pursuits
  4. Intrinsic motivation
  5. Potential enhancements of the dorsolateral prefrontal cortex

Frontal lobe[edit | edit source]

Figure 1. The frontal lobe

The frontal lobe is one of four major lobes in the human brain and is located at the front of each hemisphere. The frontal lobe is distinguished from the parietal lobe by the central sulcus, and separated from the temporal lobe by the lateral sulcus (Fuster, 2015).

The frontal lobe is further divided into functional areas. The primary motor cortex, premotor cortex, frontal eye fields, Broca’s area and the prefrontal cortex are the major functional areas within the frontal lobe.

Prefrontal cortex[edit | edit source]

The prefrontal cortex (PFC) covers the front-most part of the frontal lobe. The PFC is involved in personality expression, social behaviour, planning complex cognitive behaviour, and decision making (Fuster, 2015). The activity of the PFC is complex with researchers concluding that the PFC is responsible for executive functioning. The ability to differentiate among conflicting thoughts, separating differences between good and bad, better and best, and same and different, consequences, goal pursuits, expectations, and social norms is controlled by such executive functioning in the PFC (Fuster, 2015).

Fuster (2015) emphasised the functioning of the PFC in interpreting and representing information not readily available in the environment. The ability to represent information to pursue goals underlies all higher executive functioning. There have been several theories explaining the process the PFC undertakes utilising executive functioning. Top-down processing, the Dynamic Filtering Theory and the Integrative Theory of Prefrontal Cortex Function further explain the role of executive functioning in goal-pursuits.

The prefrontal cortex can be separated into two functionally different regions: the ventromedial prefrontal cortex (vmPFC) and the lateral prefrontal cortex (LPFC). From these two regions, the LPFC can be delineated into the dorsolateral (DLPFC) and ventrolateral (vl-PFC) areas, and the vmPFC can be delineated into the medial (mPFC) and ventral (vPFC) areas. Each of these areas are highly interconnected with areas of the brain responsible for attention, cognition, action and emotion (Fuster, 2015; Sturm, Haase & Lavenson, 2016).

Table. 1 Subdivisions of the Prefrontal Cortex
Lateral Ventromedial
Dorsolateral Ventrolateral Medial Ventral

Dorsolateral prefrontal cortex:[edit | edit source]

Figure 2. Sections of the frontal lobe

The DLPFC is a functional structure, rather than an anatomical structure, located in the middle frontal gyrus in humans. The DLPFC is a key structure responsible for many executive functions (Fuster, 2015; Striedter, 2005). Although not exclusively responsible, the DLPFC is required in all complex mental activity. The DLPFC is involved in planning, organisation, inhibition and abstract reasoning and several other executive functions (Fuster, 2015; Striedter, 2005). The DLPFC contains neural circuitry responsible for integrated responses such as sensory input, retaining short-term memory and motor signalling (Striedter, 2005). The DLPFC contains several connections to other cortices such as the temporal cortex, posterior parietal cortex, the premotor cortex and the retrosplenial cortex that allow the DLPFC to regulate brain activity, as well as be regulated by these cortices (Fuster, 2015).  


Nuvola apps korganizer.svg
Quiz Question

True or False? Attention is a function of the dorsolateral prefrontal cortex

True
False

Dorsolateral prefrontal cortex and goal-setting[edit | edit source]

The DLPFC is responsible for all new goal-directed sequences in activities involving behaviour, language, and reasoning (Fuster, 2015; Collins, 2008; Striedter, 2005). In the pursuit of goals, humans utilise prefrontal networks and interconnections in order to generate a plan of action, or schema (Fuster, 2015; Collins, 2008). This highly complex process is reliant on many cortical and subcortical brain regions that according to researchers the DLPFC initiates [missing something?] (Fuster 2015; Blumenfeld & Ranganath, 2007). The DLPFC is responsible for the structuring of behaviour and cognition in attaining biological and cognitive goals (Blumenfeld & Ranganath, 2007; Collins 2008).

As the DLPFC is at least partially responsible for integrated neuronal responses involving sensory input, retaining short-term memory, and motor signalling researchers have explained two further functions attributable to the role of the DLPFC and pursing[spelling?] goals. First, a retrospective function of short-term memory and the second, a prospective function of preparatory set (or expectation). These two functions share overlapping networks of the DLPFC and have been theorised to bridge time between sensory and motor events. Such bridging enables humans to maintain long term goals and achieve them through the control of motor output and sensory input.

The dorsolateral prefrontal cortex and working memory[edit | edit source]

Fuster (2015) concluded that the DLPFC is critically involved in forms of working memory in order to achieve a goal. The evidence primarily comes from two methodologies: selective inactivation of the DLPFC and single-cell recording. Smith and Jonides (1999) measured the activation of the DLPFC during working memory and concluded that an activation in the DLPFC supports mobilisation for future action.

In order to measure the executive role of the DLPFC in goal pursuits, researchers analysed how managing expectation and memory occur on a neuronal level. Researchers monitored the progressive increase of cell discharge and slow surface-negative potentials of subjects before a stimulus-contingent act. This indicates that memory and expectation can function simultaneously (Smith & Jonides, 1999). Such activity of cells manifests in the human ability to focus attention on a motor act to ensure efficient execution.

Figure 3. A 3D rendering of Phineas Gage's brain injury.

Current research further acknowledges the role of the DLPFC in working memory. Kobayashi (2009) analysed the influences of rewards on activity in the DLPFC in monkeys. Kobayashi (2009) concluded that DLPFC neurons are sensitive to many aspects of reward: quantity, quality, availability, and delay. Kobayashi theorised two potential possibilities for the high sensitivity of reward on the DLPFC: first, that the DLPFC receives reward information from the orbitofrontal cortex, and the second is the response of mesencephalic dopamine neurons located in the DLPFC.

Understanding the role of working memory and short-term goals on the DLPFC is critical for evaluating the role of the DLPFC and long-term goal pursuits according to Woolley and Fishbach (2016). The DLPFC has a role in the assessment of a cost-benefit analysis, and immediate rewards greater influence cost-benefit analyses. For instance, individuals attempting to lose weight may join a gym with the long-term goal to lose weight. As there is a major delay between consistent exercise and losing weight, individuals are likely to give up on their weight-loss journey. There is a tendency to evaluate the cost of time and energy against their final goal of losing weight. Such cost-benefit analysis acknowledges a major delay between reaching the reward of their goal. Conversely, when individuals can incrementally reward themselves, a cost-benefit analysis is undertaken with the benefit (or reward) having shorter delays, resulting in higher motivation of the individual. It is therefore critical to acknowledge the role of the DLPFC’s dopamine reward circuits, involving mesencephalic dopamine neurons, in planning and achieving short-term goals and the effect of achievement on long-term goals (Ballard et al., 2011).

As the DLPFC is largely responsible for many executive functions,[grammar?] it plays a pivotal role in mechanisms of self-control (Mansouri, Koechlin, Rosa & Buckley, 2017; Fishbach & Trope, 2005). Fishbach and Trope (2005) investigated how self-control over the attention and valuation of delayed rewards affected immediate temptation. Such self-control dilemmas focus on the role of perception of sensory information to influence motivation (Fishbach & Trope, 2005). For instance, a student who debates between studying (long-term reward) or partying (short-term reward) is more likely to study if they consider the delayed rewards of studying (obtained degree) against the delayed rewards of partying (likely to be none), instead of the immediate rewards for each possibility. Executive functioning relating to self-control suggests that intrinsic motivation plays a significant role in long-term goal pursuits.

The year is 1848, Phineas Gage is about to become a legend in the psychology community.

While packing a hole full of gun powder with an iron rod, the powder detonated and the iron rod was launched into Gage's head. Unbelievably, Gage survived the incident. After the incident, Gage was unlike he was earlier, his personality had changed. His misfortune became the ground work for understanding the location of particular functions of the brain (Garcia-Molina, 2012).

Goal-setting theory[edit | edit source]

Edwin Locke (1968) generated a theory measuring the effects of setting goals on performance. Consistent findings show that individuals who set specific, difficult goals, performed better than those with vague, less difficult goals. More recently, Locke and Latham (2002) have revisited goal-setting theory and have updated five basic principles in order to best achieve long-term goals:

1.    Clarity: Goals must be clear and specific.

2.    Challenge: There must be a decent level of difficulty in order to motivate individuals to strive for goals.

3.    Commitment: There must be deliberate effort to meet the goal.

4.    Feedback: Receiving information on how to best progress toward your goal influences achieving long-term goals.

5.   Task Complexity: If the task is difficult, ensure a realistic time-frame has been given to achieve and overcome obstacles.


Nuvola apps korganizer.svg
Quiz Question

True or False? It is necessary to receive feedback in order to best achieve your goal.

True
False

Motivation[edit | edit source]

Motivation can be divided into two different types of motivation: Intrinsic and Extrinsic motivation. As the purpose of this chapter is to evaluate the role of the DLPFC in long-term goal pursuits, this chapter will only display intrinsic motivation.

Intrinsic motivation[edit | edit source]

Intrinsic motivation is a behaviour that is driven by internal drives. Instead of external pressures or desires to be motivated, there is an emphasis on interest or enjoyment of the task itself (internal drives). Individuals who are intrinsically motivated are more likely to engage in a task willingly in order to improve their skills, and are more likely to achieve long term goals (Richard & Edward, 2000).

The DLPFC has a strong relationship with the dorsal anterior cingulate cortex (dACC) as both areas are responsible for monitoring errors and in behavioural adaptation. Such functioning plays a critical role in  long-term goal pursuit (Ng, 2018). As per Locke’s Goal-Setting Theory (1968), it is most beneficial for individuals to understand particular obstacles or difficulties, as well as have the perceived ability to complete a task when pursuing goals.

Dopamine is considered a key substrate of intrinsic motivation in goal-setting (Ballard et al., 2011; Ng, 2018). Attentiveness and behavioural engagement are two functions of dopamine that directly impact the functioning of intrinsic motivation (Ng, 2018). Dopamine enables the successful behaviour in accordance with goals (Ng, 2019; Ott & Nieder, 2019). There is a great reliance on the dopamine systems in the prefrontal cortex, utilising the Dopamine Reward Circuit, to regulate functioning (Ballard et al., 2011).


Nuvola apps korganizer.svg
Quiz Question

True or False? Intrinsic motivation refers to motivators such as enjoyment

True
False

Enhancements of the functioning of the DLPFC[edit | edit source]

Research has demonstrated that obscurities in the DLPFC are present in those diagnosed with mental illnesses such as schizophrenia. As a result, new information pertaining to the correction of neuronal processes is being sought after by researchers.

Natural enhancements[edit | edit source]

Kumari et al. (2011) conducted a study to measure the rate of increased activation of connections in the prefrontal brain region associated with psychotic symptoms. Kumari et al. (2011) used a functional MRI (fMRI) to see how patients processed black and white images of facial expressions such as fear and anger. The fMRI initially showed how particular increased activation of connections in the prefrontal brain region was associated with psychotic symptoms such as delusions. Patients were then required to undergo six months of cognitive behavioural therapy (CBT). After the six months, an fMRI showed that there was heightened activity between the DLPFC and the amygdala. This heightened activity demonstrated a reduction in threat processing when viewing different facial expressions. The CBT also induced greater connectivity between the dorsolateral prefrontal cortex and the post-central gyrus in the parietal lobe. This associated contributed to either full or partial remission of psychotic symptoms.

Unfortunately, this study also had several limitations. The study has been criticised for having a high potential for a type II error as there was a high attrition rate. Furthermore, the generalisability of the results into clinical practice is poor as facial affective processing tasks are not common place in clinical practice.

Despite such limitations, the results cannot be ignored and more research should be conducted regarding brain connectivity changes associated with psychotherapy, and how this may help long-term recovery from mental illness. More specifically, changes in the DLPFC’s executive functioning and cross-cortical communication must be researched

Artificial enhancements[edit | edit source]

Beyond natural enhancements to the DLPFC, a lot of research has been conducted regarding medication and transcranial direct current stimulation. Recently there has been a push in research regarding the side effects and the role of medication on the frontal lobe.

Guanfacine[edit | edit source]

Current medications such as guanfacine are currently being prescribed to individuals with ADHD (Attention Deficit Hyperactivity Disorder) (Cruz, 2010). Guanfacine focuses on the inhibition of impulsive choices through the strengthening of attention and behaviour affecting neurons in the DLPFC (Cruz, 2010). Guanfacine strengthens prefrontal cortical synaptic connectivity and enhances neuronal firing. Guanfacine has the potential to influence long-term goal pursuit through the benefits of executive functioning influencing attention.

Unfortunately there are several side effects. Common side effects includes sleepiness, constipation, drowsiness and constipation. More severe side effects can include anxiety, low blood pressure, and depression (Cruz, 2010).

Modafinil[edit | edit source]

Modafinil is another medication often used to enhance motivation of individuals diagnosed with disorders relating to motivation (Robertson & Hellriegal, 2003). Modafinil has been the target of several studies, with a focus on the effect of modafinil on dopamine and brain functioning. Zolkowska et al. (2009) found that modafinil significantly affects the dopamine transporter and acts as a dopamine reuptake inhibitor, which are known to help in the treatment of ADHD and narcolepsy.

Modafinil is known as an atypical dopamine reuptake inhibitor as there is low potential for substance abuse (Zolkowska et al., 2009). By altering dopamine functioning in the DLPFC, executive functioning decisions change and have potential to influence long-term goal pursuits.

Unfortunately much like guanfacine there are several negative side effects of modafinil including: headache, anxiousness, back pain, nausea, and sleep problems (Robertson & Hellriegal, 2003). There is also a lot of inconclusive research on the rate of addiction for the long-term use of modafinil.

Transcranial direct current stimulation[edit | edit source]

Javadi and Walsh (2012) analysed whether transcranial direct current stimulation (tDCS) affects the human working memory. Anodal and cathodal stimulation was applied over the left DLPFC. During encoding of information, anodal stimulation of the left DLPFC improved memory, whereas cathodal stimulation of the same area impaired memory performance. The results of the study indicated that active stimulation of the left DLPFC can lead to an enhancement of memorisation. Such short-term memory effects have the potential to influence long-term goal pursuits.

With each artificial enhancement, more information needs to be done measuring the effects of both medication and tDCS on long-term goal pursuits (Yang, Gao, Shi, Ye & Chen, 2017). Although information can be inferred from the functioning of the DLPFC, more conclusive research is needed. Furthermore, the side effects of medication may prove too great to warrant further investigation. 


Nuvola apps korganizer.svg
Quiz Question

True or False? Modafinil is considered a dopamine reuptake inhibitor.

True
False

Future direction for research[edit | edit source]

Future direction for research needs to focus on long-term goal pursuits. There is little research on the relationship between the DLPFC and long-term goal pursuits.

As the DLPFC is at least partially responsible for executive functioning and relies on communicating with several other cortices to function, research would benefit from further conceptualising the DLPFC. Analysing the role of the DLPFC and long-term goal pursuits may oversimplify numerous processes of executive functioning.

Future research could also consider the clinical significance of changes to the DLPFC. Current research on the relationship of CBT and the DLPFC is interesting and may prove clinically beneficial for patients. More research should measure the neuronal changes resulting from CBT. Future research may also consider the combined effect of medication and CBT on the DLPFC and how this may effect disorders such as schizophrenia and ADHD.

Conclusion[edit | edit source]

The role of the DLPFC in long-term goal pursuits is complex and involves various cross-cortical functioning. The biggest predictors of achieving long-term goals are identified as achieving short-term goals, reward systems, and cognitive differences in executive functioning. It is therefore imperative to analyse the relationship the DLPFC has with these variables. Currently, it is understood that long-term goals involve various cortices and sub-cortices.

Research currently draws inferences as to how the DLPFC effects long-term goal pursuits. These inferences are based on the functions of the DLPFC, and therefore research is concerned with the effect of a particular function on long-term goals. These functions occur cross-cortically adding to the complexity in conclusively suggesting the role of the DLPFC in long-term goal pursuits. More conclusive longitudinal studies must be conducted analysing the role of the DLPFC in order to conclusively report the role of the DLPFC in long-term goal pursuits.

See also[edit | edit source]

Motivation (Wikiversity)

Frontal Lobe (Wikiversity)

Dopamine and emotion (Wikiversity)

Transcranial Direct Current Stimulation (Wikiversity)

Goal-Setting Techniques (Wikiversity)

References[edit | edit source]

Ballard, I., Murty, V., Carter, R., MacInnes, J., Huettel, S., & Adcock, R. (2011). Dorsolateral prefrontal cortex drives mesolimbic dopaminergic regions to initiate motivated behaviour. Journal of Neuroscience. https://doi.org/10.1523/jneurosci.0895-11.2011

Blumenfeld, R., & Ranganath, C. (2007). Prefrontal cortex and long-term memory encoding: An integrative review of findings from neuropsychology and neuroimaging. The Neuroscientist, 13, 280-291. doi: 10.1177/1073858407299290

Collins, M. L. (2008). Handbook of developmental cognitive neuroscience. MIT press.

Cruz, M. P. (2010). Guanfacine extended-release tablets (Intuniv), a nonstimulant selective alpha2a-adrenergic receptor agonist for attention-deficit/hyperactivity disorder. Pharmacy and Therapeutics, 35, 448.

Fishbach, A., & Trope, Y. (2005). The substitutability of external control and self-control. Journal of Experimental Social Psychology, 41, 256-270. doi: https://doi.org/10.1016/j.jesp.2004.07.002

Fuster, J. (2015). The prefrontal cortex. Academic Press.

García-Molina, A. (2012). Phineas Gage and the enigma of the prefrontal cortex. Neurología (English Edition), 27, 370-375. Doi: https://doi.org/10.1016/j.nrleng.2010.03.002

Javadi, A. H., & Walsh, V. (2012). Transcranial direct current stimulation (tDCS) of the left dorsolateral prefrontal cortex modulates declarative memory. Brain stimulation, 5, 231-241. Doi: https://doi.org/10.1016/j.brs.2011.06.007

Kobayashi, S. (2009). Reward neurophysiology and primate cerebral cortex. Doi: https://doi.org/10.1016/B978-008045046-9.01559-X

Kumari, V., Fannon, D., Peters, E. R., Ffytche, D. H., Sumich, A. L., Premkumar, P., ... & Kuipers, E. (2011). Neural changes following cognitive behaviour therapy for psychosis: a longitudinal study. Brain, 134. doi: https://doi.org/10.1093/brain/awr154

Locke, E. A., & Latham, G. P. (2002). Building a practically useful theory of goal setting and task motivation: A 35-year odyssey. American psychologist, 57, 705.

Mansouri, F. A., Koechlin, E., Rosa, M. G., & Buckley, M. J. (2017). Managing competing goals—a key role for the frontopolar cortex. Nature Reviews Neuroscience, 18, 645. Doi:https://doi.org/10.1038/nrn.2017.111

Ng, B. (2018). The neuroscience of growth mindset and intrinsic motivation. Brain sciences, 8, 20. Doi: https://doi.org/10.3390/brainsci8020020

Ott, T., & Nieder, A. (2019). Dopamine and cognitive control in prefrontal cortex. Trends in cognitive sciences. doi :https://doi.org/10.1016/j.tics.2018.12.006

Robertson, P., & Hellriegel, E. T. (2003). Clinical pharmacokinetic profile of modafinil. Clinical pharmacokinetics, 42, 123-137. Doi:10.2165/00003088-200342020-00002

Ryan, R. M., & Deci, E. L. (2000). Intrinsic and extrinsic motivations: Classic definitions and new directions. Contemporary educational psychology, 25, 54-67.doi:10.1006/ceps.1999.1020

Smith, E. E., & Jonides, J. (1999). Storage and executive processes in the frontal lobes. Science, 283, 1657-1661. doi:http://dx.doi.org/10.1126/science.283.5408.1657

Striedter, G. F. (2005). Principles of brain evolution. Sinauer Associates.

Sturm, V. E., Haase, C. M., & Levenson, R. W. (2016). Emotional dysfunction in psychopathology and neuropathology: Neural and genetic pathways. In Genomics, Circuits, and Pathways in Clinical Neuropsychiatry. Academic Press. doi: https://doi.org/10.1016/B978-0-12-800105-9.00022-6

Woolley, K., & Fishbach, A. (2017). Immediate rewards predict adherence to long-term goals. Personality and Social Psychology Bulletin, 43, 151-162. Doi: 10.1177/0146167216676480

Yang, X., Gao, M., Shi, J., Ye, H., & Chen, S. (2017). Modulating the activity of the DLPFC and OFC has distinct effects on risk and ambiguity decision-making: A tDCS Study. Frontiers in psychology, 8, 1417. doi:10.3389/fpsyg.2017.01417

Zolkowska, D., Jain, R., Rothman, R. B., Partilla, J. S., Roth, B. L., Setola, V., & Baumann, M. H. (2009). Evidence for the involvement of dopamine transporters in behavioral stimulant effects of modafinil. Journal of Pharmacology and Experimental Therapeutics, 329, 738-746. doi: https://doi.org/10.1124/jpet.108.146142

External links[edit | edit source]

Study on the DLPFC and motivation

Tedx Talk on vision, goals and willpower.