Written by Yagmur Delal Cengiz
Think about the people around you–your friends, family, teacher, etc. All — having a unique combination of behaviors, feelings, and thoughts — are distinct individuals. Some of them like to socialize and meet new people, and some of them prefer hanging out in small friend groups. Some easily get worried, and some do not seem stressed out even in quite serious situations. Some of your friends can be outgoing, silent, energetic, or patient. Every time we use one of these adjectives to describe someone in our immediate vicinity, we are referring to that person's personality.
To investigate human behavior, personality psychologists have developed several approaches to how an individual's pattern of thoughts, behavior, and feelings can be categorized and understood. One of the popular approaches for representing the human trait–specific characteristics of a person–is the Five Factor Model. As it was based on the lexical hypothesis–a theory that claims human traits are encoded in language with specific words–The Five Factor theory was dedicated to explaining human personality with a limited variety of words. The model utilizes five basic factors to describe most personality traits:
Neuroticism, Openness to Experiment, Extraversion, Agreeableness, and Conscientiousness (Roccas, 2002). Neuroticism, which represents the degree to which a person perceives the world as distressing, threatening, and unsafe(Kwon, Sangil., 2007), is a strong correlate of a wide range of mental and physical disorders, as well as comorbidity and the frequency with which mental and general health services are used (Kessler, Chiu, Demler, & Walters, 2005). Additionally, neuroticism appears to be a predictor of the quality and length of our lives (Lahey BB., 2009), and it is this human trait that will be examined for its neurological basis in this article.
As a result of its influence on different aspects of society, such as being potent to give promising results in research regarding public health(Smith, T. W., 2006), extending the knowledge about neuroticism, and comprehension of its possible effects among groups are worth researching. Due to the same reason, factors that increase an individual’s probability of scoring high on neuroticism have been investigated for decades.
Various theorems had been stated over time to explain the association between neuroticism and the brain's chemical or physical structure. First, it was proposed that neuroticism was a result of low thresholds for the activation of the systems connecting the cerebral cortex and visceral brain (Eysenck, 1967). More clearly, the visceral brain– the part mainly responsible for emotional regulations–was thought to need fewer levels of stimulation in people high on neuroticism making these people more likely to experience negative emotions even in slightly stressful situations.
Another factor affecting an individual's score on neuroticism was the structure of the brain. To gather comparable data from high and low neuroticism subjects, research was conducted that utilized neuroimaging techniques such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) (Canli T., 2001; Servaas, 2013). Throughout the research especially the brain parts that have varied levels of control over emotional responses were examined such as the amygdala, anterior and mid-cingulate cortex, medial prefrontal cortex, and hippocampus (DeYoung, 2010).
Hence, studies with these parts of the brainpresented the association between systems controlling sensitivity to punishment and threats (Klein, 2019). Some other research revealed that levels of neuroticism were associated with increased cortical thickness as well as decreased area and folding in particular parts of the cortex, such as the prefrontal-temporal cortices at the front of the brain could be an indicator of high neuroticism, which may predispose persons to develop neuropsychiatric diseases (R. Ricelli, 2017).
(Image credit: https://www.cam.ac.uk/research/news/personality-traits-linked-to-differencesin-brainstructu%20re#:~:text=The%20researchers%20found%20that%20high,the%20front%20of%20t he%20bra%20in )
On the other hand, some studies discussing the link between neuroticism and cortical thickness gave different outcomes for female and male subjects. According to the research, with age, women who scored higher on neuroticism demonstrated a thinner anterior cingulate cortex–a part responsible for decision-making and self-regulation of emotion (Stevens, F. L., 2001)–than women who scored lower on neuroticism. In male subjects, the opposite correlation was observed though; the cortex in this area was thicker with age in men who scored high on neuroticism, whereas it was thinner in men who scored low on neuroticism (Sweeney, 2019).
(Image credit: https://www.flintrehab.com/anterior-cingulate-cortex-damage/ )
All in all, acquiring more advanced knowledge of neuroticism is a significant issue considering the influence of people with high neuroticism scores on their community. While environmental influences such as experiencing traumatizing and psychologically challenging situations in earlier stages of life are also a key element for an increased tendency of showing high neuroticism, the neurobiological analysis of the trait is necessary for a better understanding of neuroticism.
Keywords: Neuroticism, Five Factor Model, Cerebral Cortex, Personality Traits
Refferences:
Roccas, S., Sagiv, L., Schwartz, S. H., & Knafo, A. (2002). The Big Five Personality Factors
and Personal Values. Personality and Social Psychology Bulletin, 28(6), 789–801.
Weed, Nathan & Kwon, Sangil. (2007). Neuroticism.
Kessler RC, Chiu WT, Demler O, Walters EE. Prevalence, Severity, and Comorbidity of 12-Month DSM-IV Disorders in the National Comorbidity Survey Replication. Arch Gen
Psychiatry. 2005;62(6):617–627. doi:10.1001/archpsyc.62.6.617.
Lahey BB. Public health significance of neuroticism. Am Psychol. 2009
May-Jun;64(4):241-56. doi: 10.1037/a0015309. PMID: 19449983; PMCID: PMC2792076.
Smith, T. W. (2006). Personality as risk and resilience in physical health. Current directions in psychological science, 15(5), 227-231.
Eysenck, H.J., 1967. The Biological Basis of Personality. Charles C. Thomas, Springfield, IL. Canli T, Zhao Z, Desmond JE, Kang E, Gross J, Gabrieli JD. An fMRI study of personality influences on brain reactivity to emotional stimuli. Behav Neurosci. 2001 Feb;115(1):33-42.doi: 10.1037/0735-7044.115.1.33. PMID: 11256451.
Servaas, M. N., van der Velde, J., Costafreda, S. G., Horton, P., Ormel, J., Riese, H., &
Aleman, A. (2013). Neuroticism and the brain: a quantitative meta-analysis of neuroimaging studies investigating emotion processing. Neuroscience and biobehavioral reviews, 37(8),1518–1529.
https://www.sciencedirect.com/science/article/abs/pii/S0149763413001255?via%3Dihub.DeYoung, C. G., Hirsh, J. B., Shane, M. S., Papademetris, X., Rajeevan, N., & Gray, J. R.(2010). Testing predictions from personality neuroscience. Brain structure and the big five.
Psychologicalscience,21(6),820–828.
https://journals.sagepub.com/doi/10.1177/0956797610370159
Klein, R. J., & Robinson, M. D. (2019). Neuroticism as mental noise: Evidence from a continuous tracking task. Journal of personality, 87(6), 1221–1233.
Roberta Riccelli, Nicola Toschi, Salvatore Nigro, Antonio Terracciano, Luca Passamonti,Surface-based morphometry reveals the neuroanatomical basis of the five-factor model ofpersonality, Social Cognitive and Affective Neuroscience, Volume 12, Issue 4, April 2017,
Pages 671–684, https://academic.oup.com/scan/article/12/4/671/2952683.
Sweeney, M., Tsapanou, A., & Stern, Y. (2019). Regional cortical thickness and neuroticismacross the lifespan. Psychiatry research. Neuroimaging, 286, 39–44.
https://www.sciencedirect.com/science/article/abs/pii/S092549271830204X?via%3Dihub
Stevens, F. L., Hurley, R. A. & Taber, K. H. Anterior cingulate cortex: Unique role incognition and emotion. J. Neuropsychiatry. Clin. Neurosci. 23, 120–125.
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