Viewing the Personality Traits Through a Cerebellar Lens: a Focus on the Constructs of Novelty Seeking,Harm Avoidance,and Alexithymia

The variance in the range of personality trait expression appears to be linked to structural variance in specific brain regions. In evidencing associations between personality factors and neurobiological measures, it seems evident that the cerebellum has not been up to now thought as having a key role in personality. This paper will review the most recent structural and functional neuroimaging literature that engages the cerebellum in personality traits, as novelty seeking and harm avoidance, and it will discuss the findings in the context of contemporary theories of affective and cognitive cerebellar function. By using region of interest (ROI)- and voxel-based approaches, we recently evidenced that the cerebellar volumes correlate positively with novelty seeking scores and negatively with harm avoidance scores. Subjects who search for new situations as a novelty seeker does (and a harm avoiding does not do) show a different engagement of their cerebellar circuitries in order to rapidly adapt to changing environments. The emerging model of cerebellar functionality may explain how the cerebellar abilities in planning, controlling, and putting into action the behavior are associated to normal or abnormal personality constructs. In this framework, it is worth reporting that increased cerebellar volumes are even associated with high scores in alexithymia, construct of personality characterized by impairment in cognitive, emotional, and affective processing. On such a basis, it seems necessary to go over the traditional cortico-centric view of personality constructs and to address the function of the cerebellar system in sustaining aspects of motivational network that characterizes the different temperamental traits.     

Temperament and character dimensions in patients with social phobia: patterns of change following treatments?

The aim of this study was to examine Temperament and Character Inventory (TCI) profiles in patients with social phobia (DSM-IV) and to outline patterns of change following intensive group cognitive therapy (IGCT), individual cognitive therapy (ICT) and treatment as usual (TAU). One hundred patients recruited by advertisements in local papers were randomized to IGCT, ICT and TAU. Patients (n=59) who completed diagnostic evaluation and TCI assessments at baseline and 1-year follow-up were examined in this study. Patients differed from healthy controls in novelty seeking (NS), harm avoidance (HA), self-directedness (SD), cooperativeness (C), and self-transcendence (ST). Treatments overall were associated with decrease in HA, while increase in SD was observed after psychotherapy only. Reduced social anxiety was correlated with decrease in HA and increase in SD. High HA at baseline was related to poor treatment outcome in all treatments. To conclude, patients with social phobia show a temperamental vulnerability for developing anxiety and character traits associated with personality disorders. Successful treatment is related to decrease in HA and increase in SD. High HA at baseline may suggest a need for extensive treatment in order to achieve remission.     

Personality disorders and the trimensional personality questionnaire factors in major depressive disorder

We assessed the potential relationship between personality disorder (PD) clusters, as assessed by the SCID-II, and temperamental traits assessed by the Tridimensional Personality Questionnaire (TPQ) among a well-characterized, unmedicated cohort of outpatients with major depressive disorder (MDD). The TPQ and SCID-II were administered to 263 depressed outpatients (mean age = 39.9 +/- 10.5 years; women = 139, 53%; initial 17-item Hamilton Rating Scale for Depression = 19.6 +/- 3.4) who currently met criteria for MDD and who were enrolled in an 8-week treatment trial. The multiple linear regression method was used to evaluate the relationship between TPQ factors and personality disorder clusters, controlling for age, gender, and initial 17-item Hamilton Rating Scale for Depression score as necessary. Among outpatients with MDD, meeting criteria for a Cluster A PD diagnosis was related to high harm avoidance (HA) scores, as well as low reward dependence and novelty seeking (NS) scores. Additionally, high HA scores were associated with meeting criteria for a Cluster C PD diagnosis, while high NS scores were associated with meeting criteria for a Cluster B PD diagnosis. Certain temperament traits, especially HA and NS, appear to be associated with specific patterns of personality clusters among depressed patients.     

Polymorphisms in the dopamine, serotonin, and norepinephrine transporter genes and their relationship to temperamental dimensions measured by the Temperament and Character Inventory in healthy volunteers

There is evidence for an association between polymorphisms of monoamine transporter genes and temperamental personality traits. Recent findings have shown that interaction of allelic variants of the different genes may contribute to the personality factors. We studied the association between temperamental personality dimensions measured with the Temperament and Character Inventory (TCI) and polymorphisms of the dopamine (DAT), norepinephrine (NET) and serotonin (5-HTT) transporter genes in 127 healthy Polish volunteers. There were no significant differences between means of TCI temperamental dimensions (novelty seeking, reward dependence, persistence and harm avoidance) and the transporter genes compared by ANOVA. There were some significant associations between genotypes and TCI subdimensions. Individuals carrying the A9/A9 DAT genotype have lower RD4 scores (dependence vs. independence) than A10/A10 individuals (3.0 +/- 1.4 vs. 3.5 +/- 1.3); p = 0.01. Examining 5-HTT gene promoter polymorphism, heterozygous individuals (l/s) and individuals with 44-bp deletion (s/s) scored significantly lower in the HA1 subdimension (anticipatory worry and pessimism vs. uninhibited optimism; 4.3 +/- 2.3 vs. 5.5 +/- 2.6) in comparison with individuals without deletion (l/l); p = 0.021. The NET transporter gene polymorphism showed no significant association with any of the temperamental TCI subdimensions.     

Personality dimensions measured using the Temperament and Character Inventory (TCI) and NEO-FFI on a Polish sample

The results of two self-administered, paper-and-pencil tests based on biosocial theory of personality have been compared simultaneously: the Temperament and Character Inventory (TCI) and NEO Five Factor Inventory (NEO-FFI). The stability of the personality dimensions was assessed across age, sex and education level samples in a group of 406 Polish adults with major mental diseases excluded by use of PRIME-MD questionnaire. Significant effects of age, sex, and education have been found while comparing personality dimensions in both temperamental (novelty seeking, NS; harm avoidance, HA; reward dependence, RD; persistence, P) and character scales (cooperativeness, C; self-transcendence, ST) in TCI. Among subscales of temperament only NS1, RD4 were stable according to concerning factors. All converted to their age and sex norms NEO-FFI dimensions were stable according to sex. Extraversion scale was changeable depending on age (p = 0.04). Neuroticism dimension was a little higher in lower educated group (p = 0.035).To sum up, it was concluded that sex- and age-specific norms for the dimensions of the Polish version of TCI are necessary considering the established significant differences. Particular personality genetic studies should account for age, sex and also educational differences in their methods of associative studies. CONCLUSIONS: In the exploration of personality dimensions on healthy volunteers the Polish version of NEO-FFI corresponds better than TCI to theory of stability and genetic determinants of human personality. As the study included persons with excluded major mental diseases, the sample is appropriate to provide a control group in the research of psychiatric patients using both TCI and NEO-FFI. SIGNIFICANT OUTCOMES: TCI scores for persons with excluded mental disease are highly changeable depending on age, sex and education. Adjusted to sex and age scores NEO-FFI corresponded better than TCI to stability and genetic determinants of human personality.     

Volume of left amygdala subregion predicted temperamental trait of harm avoidance in female young subjects. A voxel-based morphometry study

We investigated the relationship between temperamental predisposition and brain structure by using a standard questionnaire and high-resolution T1-weighted magnetic resonance image (MRI) in normal young volunteers. Fifty-six subjects completed the Japanese version of the Temperament and Character Inventory (TCI, 125 items) and underwent an MRI acquisition of the brain. The gray matter (GM) was extracted from the whole brain image of the subjects and normalized to the standard brain template using statistical parametric mapping and the optimized voxel-based morphometry (VBM) method. When the score on the harm avoidance (HA) subscale was used as a dependent variable, the multiple regression analysis revealed that the HA score positively correlated with the volume of the part of left amygdala. The region-of-interest analysis showed that the correlation was significant in the female subjects but not in the male subjects. The correlation was significant even after the effects of age, depression score, and total GM volume were taken into account. The differential correlation between the sexes may be caused by differences in hormonal condition and the vulnerability of women to socio-psychological stress. In addition, the novelty seeking (NS) score positively correlated with the GM of the left middle frontal gyrus. The volume of the tail of the right caudate nucleus positively correlated with the reward dependence (RD) score. With regard to the NS and RD scores, no significant sex difference was observed in the correlation. These results indicate that the temperamental traits measured using the questionnaire may have a morphological basis in the human brain.     

Personality factors in depressive disorders: contribution of the psychobiologic model developed by Cloninger

The psychobiological model of personality developed by Cloninger, including four dimensions of temperament and three dimensions of character, allows to explore personality factors associated with depressive disorders. The three main dimensions of temperament are Novelty Seeking (NS), ie the tendency towards excitement in response to novel or rewarding stimuli, Harm Avoidance (HA) hypothesized to represent the tendency to respond intensely to signals of adverse stimuli, and Reward Dependence reflecting the tendency to respond intensely to signals of reward and to maintain behavior previously associated with reward. These personality traits are hypothetically related to underlying neurotransmetter systems (especially NS to dopaminergic function and HA to serotonergic function). The two main dimensions of character are Self-Directedness (SD) and Cooperativeness (C), measuring maturity traits respectively concerning individual and social adaptation; thus they are negatively correlated with the risk of personality disorder for a given patient. Many studies have been carried out with the Temperament and Character Inventory (TCI), or with the previous Tridimensional Personality Questionnaire (TPQ), in depressive disorders with cross-sectional but also with short-term and long-term longitudinal designs. They show primarily that patients with history of depressive disorders, even in euthymic phase, have very high Harm Avoidance scores. In prospective studies conducted in depressive patients, even after remission of the depressive episodes, the Harm Avoidance scores are lower than before treatment, but still elevated compared to the general population. The patients who fail to respond to antidepressant treatments have generally higher Harm Avoidance scores before treatment than the others. Overall, various results support four types of potent relationships between Harm Avoidance and depression: an influence of state on trait measure, a pathoplastic effect of Harm Avoidance on depressive expression, a vulnerability model (Harm Avoidance representing a susceptibility factor for depression), and a scar model with elevated Harm Avoidance scores even after remission of acute depressive symptoms. Other temperament dimensions, Novelty Seeking and Reward Dependence, are not consistently associated with depression characteristics nor affected by state effects, but Self-Directedness character dimension is often low when compared to subjects without depressive disorders, reflecting maladaptive personalities frequently associated to depressive disorders. Some studies suggest that low Self-Directedness scores can be predictive of suicidal behaviors. In cross-sectional studies, Harm Avoidance scores are highly positively correlated with depression intensity (r=0.23 to 0.67) and Self-Directedness scores are highly negatively correlated with depression (r=- 0.37 to - 0.60). Some studies suggest that the temperamental dimensions assessed by the TCI could have a predictive value for the response to antidepressants treatments, but this result is controversial and needs further research. For example, a study conducted in 84 patients with major depressive disorder showed that temperament type based on TPQ traits explained 25% of the response to treatment variance: patients with high scores on both Harm Avoidance and Reward Dependence had a favourable response to either clomipramine or desipramine. Studies of the relationship of temperament dimensions to biological markers of depression have also been published. It has been shown for example that Reward Dependence and Harm Avoidance scores are significantly predictive of morning hypercortisolemia in depressed subjects. More specifically, correlations have been obtained between platelet serotonergic markers (5-HT2a receptors) and Harm Avoidance scores also in depressed patients. In conclusion, Harm Avoidance seems to be a vulnerability factor or at least an associated factor to depressive disorders. This temperament dimension is supposed to be highly heritable, and to be linked to the serotonergic system variations.     

Dimensional personality assessment of the members of the French junior national team of road cycling

The high-standard sport practice requires an optimum functioning level of the individual in all its physiological systems as a whole. If the physical program training progressed much these last years, the techniques of mental preparations are still very heterogeneous and are not based on any validated procedures, based only on individual practices. Nevertheless, the majority of athletes and trainers stress the major importance of "mental" in the realization of performances. One of the obstacles in the mental training of the athletes is the difficulty in finding tools making it possible to evaluate and measure the psychic state of the individual and its mode of coping and adjustment, apart from any psychopathology. Few studies have been carried out on applicability of the personality questionnaires derived from the current dimensional models in these populations. Our study aimed to describe the personality of the members of the french junior team of road cycling, using the Temperament and Character Inventory (TCI) developed by Cloninger to explore the seven dimensions of his psychobiologic model of personality. In this model, four dimensions are temperament factors, and three are character factors. The three main dimensions of temperament are Novelty Seeking (NS), ie the tendency towards excitement in response to novel or rewarding stimuli, Harm Avoidance (HA) hypothesized to represent the tendency to respond intensely to signals of adverse stimuli, and Reward Dependence reflecting the tendency to respond intensely to signals of reward and to maintain behavior previously associated with reward. These personality traits are hypothetically related to underlying neurotransmitter systems (especially NS to dopaminergic function and HA to serotonergic function). The two main dimensions of character are Self-Directedness (SD) and Cooperativeness (C), measuring maturity traits respectively concerning individual and social adaptation. In this study, we used a computerized version of the TCI in a sample of 18 racing cyclists, ie all the members of the french junior national team. Their results were compared to those of 26 male, young, community subjects, derived from the french normative validation sample of the TCI. Mean comparisons were performed with the Mann-Whitney test, with Bonferroni correction for multiple comparisons. A significant difference between subjects and controls was obtained for Reward Dependence (p<0.0001), attachment RD3 (p<0.0001), and dependence RD4 (p<0.0025). No significant difference appeared between both groups for the other temperament or character dimensions. Based on temperamental Cloninger typology, the type "passionate" appeared to be the most frequent in this sample (55.6%). These results suggested that the TCI can be easily and usefully used in athletes, and that the personality profile of young competitive cyclists is not abnormal except a high level of reward dependence. Numerous applications can be derived from this use: the development of specific and personalized mental training, the screening and prevention of psychological vulnerability.     

No association between the TPH A218C polymorphism and personality traits in Japanese healthy subjects

It has been suggested that the central serotonergic activity is implicated in personality traits. Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in serotonin synthesis. In the present study, the association between the TPH A218C polymorphism and personality traits assessed by the Temperament and Character Inventory (TCI) was examined in 345 Japanese healthy subjects. The TPH A218C polymorphism was determined by a PCR-RFLP method. There were no significant differences in the seven dimension scores of TCI among the A/A, A/C, and C/C genotype groups by the one-way ANOVA. There was a significant negative correlation between age and the NS scores. Females showed significantly higher scores of HA, RD, and ST, and significantly lower scores of SD than males. The multiple regression analysis using age, gender, and the TPH genotype as independent variables also showed no significant association between any dimension score and the genotype. The present study thus suggests that the TPH A218C polymorphism does not affect personality traits in Japanese healthy subjects.     

The five factors of personality and regional cortical variability in the baltimore longitudinal study of aging

Although personality changes have been associated with brain lesions and atrophy caused by neurodegenerative diseases and aging, neuroanatomical correlates of personality in healthy individuals and their stability over time have received relatively little investigation. In this study, we explored regional gray matter (GM) volumetric associations of the five‐factor model of personality. Eighty‐seven healthy older adults took the NEO Personality Inventory and had brain MRI at two time points 2 years apart. We performed GM segmentation followed by regional analysis of volumes examined in normalized space map creation and voxel based morphometry‐type statistical inference in SPM8. We created a regression model including all five factors and important covariates. Next, a conjunction analysis identified associations between personality scores and GM volumes that were replicable across time, also using cluster‐level Family‐Wise‐Error correction. Larger right orbitofrontal and dorsolateral prefrontal cortices and rolandic operculum were associated with lower Neuroticism; larger left temporal, dorsolateral prefrontal, and anterior cingulate cortices with higher Extraversion; larger right frontopolar and smaller orbitofrontal and insular cortices with higher Openness; larger right orbitofrontal cortex with higher Agreeableness; larger dorsolateral prefrontal and smaller frontopolar cortices with higher Conscientiousness. In summary, distinct personality traits were associated with stable individual differences in GM volumes. As expected for higher‐order traits, regions performing a large number of cognitive and affective functions were implicated. Our findings highlight personality‐related variation that may be related to individual differences in brain structure that merit additional attention in neuroimaging research. Hum Brain Mapp 34:2829–2840, 2013. © 2012 Wiley Periodicals, Inc.     

Adolescent attachment styles and their relation to the temperament and character traits of personality in a general population.

Attachment styles as well as personality traits in adolescents and adults have been found to be associated with their health outcomes and with their personality pathology. In this cross-sectional exploratory study, we study the relationship between attachment styles that derive from our data employing the items of Feeney et al. (1994) self-report attachment style questionnaire (ASQ), and personality traits given by the junior version of Cloninger et al. (1993) self-report temperament and character inventory (TCI), in a sample of 426 adolescents (54% females) from a general population. The secure attachment style was correlated significantly negatively with the personality trait harm avoidance (HA), but significantly positively with the personality traits novelty seeking (NS), reward dependence (RD), cooperativeness (CO) and self-transcendence (ST). The preoccupied (anxious/ambivalent) attachment style was correlated significantly positively with HA and NS, but significantly negatively with self-directedness (SD). The fearful-avoidant category was correlated significantly negatively with NS. Our five-factor solution of the attachment styles and their relation to the TCI point towards a need for a modification of the two-axis, four-category attachment model of Bartholomew (1990) and Bartholomew and Horowitz (1991), with their category dismissing-avoidant replaced by the two categories defined here as dismissing relations (correlated significantly negatively with CO) and dismissing others (correlated significantly negatively with RD and significantly positively with SD).     

Relationships between temperament dimensions in personality and unconscious emotional responses.

BACKGROUND: In addition to character dimensions, personality includes temperament dimensions, defined as individual differences in implicit associative learning responses to environmental stimuli processed by unconscious memories. We examined whether temperament dimensions were associated with patterns of unconscious emotional responses of an autonomic nature. METHODS: From 70 healthy men, high and low novelty-seeking (NS) groups and high and low harm-avoidance (HA) groups were selected using scores on the Tridimensional Personality Questionnaire measuring temperament dimensions. Emotionally negative, neutral, and positive visual stimuli were presented subliminally using backward masking, and skin conductance responses (SCRs) were measured as an autonomic index of emotional responses. Skin conductance responses to the three emotional stimulus conditions were compared between groups. RESULTS: Skin conductance responses in the high NS group were significantly greater than in the low NS group when positive or negative emotional stimuli were presented but not neutral stimuli. Skin conductance responses in the high HA group were significantly greater than in the low HA group for stimuli of all three valences. CONCLUSIONS: Autonomic response patterns to unconscious emotional perception differed between NS and HA, suggesting that different dimensions of temperament may be associated with different patterns of unconscious emotional responses. Novelty seeking and HA may be associated with specificity and susceptibility of preattentive emotional perception, respectively.     

Personality traits and schizophrenia: evidence from a case-control study and meta-analysis

Personality is considered to be an important aspect of schizophrenia, primarily because it may influence patients' symptoms and social functioning. Specific personality traits are related to schizophrenia. The Temperament and Character Inventory (TCI) measures four traits of temperament - novelty seeking (NS), harm avoidance (HA), reward dependence (RD) and persistence (PS) - and three traits of character - self-directedness (SD), cooperativeness (CO) and self-transcendence (ST). We investigated associations between schizophrenia and personality traits using the TCI in a Japanese case-control sample (99 patients and 179 controls). Patients with schizophrenia scored higher on HA and ST and lower on NS, RD, SD and CO compared with controls in our case-control sample. We then performed a meta-analysis of samples from the published literature and our sample (384 patients and 656 controls). We found no evidence of heterogeneity among studies, except for NS in the overall population. Possible associations between personality traits (HA, RD, PS, SD, CO and ST) and schizophrenia were revealed. The effect sizes (Hedges' g) of the temperament traits were 0.98 for HA, -0.43 for RD and -0.23 for PS, and those of the character traits were -0.96 for SD, -0.47 for CO and 0.61 for ST. These findings suggest that patients with schizophrenia have a unique temperament and character profile compared with the general population.     

Functional connectivity with the anterior cingulate is associated with extraversion during the emotional Stroop task

Abstract

Previous research has investigated the association of personality traits with brain activation in response to emotional stimuli. Our current research efforts are directed at understanding the temporal dynamics of networks of structures associated with particular personality traits, and gain insights into the functional contributions of more narrowly defined trait-facets that comprise these personality traits. To begin this process, we conducted a functional magnetic resonance imaging (fMRI) study using an emotional attention task (emotional Stroop paradigm) and addressed the question whether individual differences in extraversion and its lower-level facets were associated with differences in activation, and in functional connectivity, of the anterior cingulate (AC) cortex. We replicated our earlier finding that extraversion was associated with increased AC activation to positive, relative to neutral, word stimuli, but now show that distinct facets of extraversion can account for this association. When analyzing for functional connectivity, we found that greater extraversion across individuals was associated with greater functional connectivity between the AC and the inferior parietal lobule, and that this association could also be accounted for by distinct facets of extraversion. Our data suggest that extraversion and some of its lower-level facets are associated with individual differences across a network of structures believed to be critical in cognitive and affective processing.     

Functional connectivity with the anterior cingulate is associated with extraversion during the emotional Stroop task

Previous research has investigated the association of personality traits with brain activation in response to emotional stimuli. Our current research efforts are directed at understanding the temporal dynamics of networks of structures associated with particular personality traits, and gain insights into the functional contributions of more narrowly defined trait-facets that comprise these personality traits. To begin this process, we conducted a functional magnetic resonance imaging (fMRI) study using an emotional attention task (emotional Stroop paradigm) and addressed the question whether individual differences in extraversion and its lower-level facets were associated with differences in activation, and in functional connectivity, of the anterior cingulate (AC) cortex. We replicated our earlier finding that extraversion was associated with increased AC activation to positive, relative to neutral, word stimuli, but now show that distinct facets of extraversion can account for this association. When analyzing for functional connectivity, we found that greater extraversion across individuals was associated with greater functional connectivity between the AC and the inferior parietal lobule, and that this association could also be accounted for by distinct facets of extraversion. Our data suggest that extraversion and some of its lower-level facets are associated with individual differences across a network of structures believed to be critical in cognitive and affective processing.     

An interaction between the serotonin transporter promoter region and dopamine transporter polymorphisms contributes to harm avoidance and reward dependence traits in normal healthy subjects

Summary. There is evidence for an association between polymorphisms of serotonin- and dopamine-related genes and temperamental personality traits. Recent findings have shown that interactions between allelic variants of the different genes may contribute to personality traits. We examined the effects of serotonin transporter-linked promoter region (5-HTTLPR) and dopamine transporter (DAT1) gene polymorphisms for associations with the Temperament and Character Inventory (TCI) temperament subscales in 209 Koreans. We found that the variants of 5-HTTLPR interacted with the DAT1 gene polymorphism to influence the HA and RD temperament subscales of TCI. Neither of these two genes affected any subscales of TCI alone. Controlling for the effects of gender and age, we found significant interactions between 5-HTTLPR and DAT1 genes on Harm Avoidance (HA) and Reward Dependence (RD) as measured by the TCI (Hotelling’s Trace = 3.0, P = 0.02). In the presence of the DAT1 10/10 genotype, subjects of group L of 5-HTTLPR had a significantly higher HA score and significantly lower RD score than those of group S (F = 5.04, df = 1, p = 0.03 and F = 8.35, df = 1, p = 0.004, respectively). These findings suggest that the variants of 5-HTTLPR interacted with the DAT1 gene polymorphism to influence the HA and RD temperament subscales of TCI.     

Gender difference in relationship between anxiety-related personality traits and cerebral brain glucose metabolism

Recent functional neuroimaging studies have suggested that specific brain regions might be associated with the formation of anxiety-related personality traits, which are well known to be influenced by gender. Such anxiety-related personality traits are one of the representative predisposing factors for mood and anxiety disorders, whose incidence is also known to be much influenced by gender. However, little is known about the gender differences in brain function related to anxiety-related personality traits. The aim of the present study was to examine gender-related differences in the pattern of the relationships between an anxiety-related personality trait and cerebral brain glucose metabolism. Regional brain glucose metabolism was measured using [¹⁸F]fluorodeoxyglucose positron emission tomography in 102 healthy subjects (65 males and 37 females). An anxiety-related trait was assessed using the Temperament and Character Inventory dimension Harm Avoidance (HA). HA was negatively correlated with glucose metabolism in the anterior portion of the ventromedial prefrontal cortex (vmPFC) in females but not in males. The anterior vmPFC may be a possible neural target for the prevention or therapy of emotional disorders, especially in females.     

An interaction between the norepinephrine transporter and monoamine oxidase A polymorphisms, and novelty-seeking personality traits in Korean females

The personality traits associated with the noradrenergic system have not yet been clearly established. In the present study, we investigated the variable number of tandem repeats (VNTR) polymorphism of the norepinephrine transporter (NET) and monoamine oxidase A (MAOA), which are major components of the adrenergic system, to elucidate their relationship with personality. A total of 245 normal female Koreans (age 23.05+/-3.07 years, mean+/-SD) volunteered to take part in this study. They filled out a Korean version of the Temperament and Character Inventory (TCI) and were genotyped for the NET and MAOA-VNTR; the NET T-182C and MAOA-uVNTR polymorphisms were checked. We found significant main effect of NET genotype on novelty seeking (NS) score (F=5.43, p=0.021) and significant interaction between the NET and MAOA-uVNTR polymorphisms on NS score (F=11.06, p=0.001). However, there were no relationship between MAOA-uVNTR polymorphisms and NS score, and no association with other temperamental dimensions and these two polymorphisms. Our findings suggest that this functional polymorphism in the noradrenergic gene is associated with novelty seeking in Korean females.     

Personality dimensions in social phobics with or without depression

OBJECTIVE: This study investigated the personality traits of social phobics using the Temperament and Character Inventory (TCI). METHOD: A sample of 178 social phobics was assessed with the TCI, and compared with controls. The patients were classified into two groups, according to the absence (SP group) or to the presence (SP+D group) of depression. RESULTS: We found significant elevated scores for harm avoidance (HA) in social phobics when compared with controls (16.2 +/- 2.7), in both the SP (26.2 +/- 3.5), and the SP+D (28.9 +/- 4.7), groups. Lower self-directedness scores were found in the SP and in the SP+D groups when compared with the controls. Patients with the generalized type of social phobia had higher HA scores as compared with other social phobics. CONCLUSION: The personality profile obtained in these social phobics, whatever their depressive symptomatology, reflects a dramatically anxious and avoidant temperament associated to an immature character.     

Combined fractional anisotropy and subcortical volumetric abnormalities in healthy immigrants to high altitude: A longitudinal study

The study of individuals at high‐altitude (HA) exposure provides an important opportunity for unraveling physiological and psychological mechanism of brain underlying hypoxia condition. However, this has rarely been assessed longitudinally. We aim to explore the cognitive and cerebral microstructural alterations after chronic HA exposure. We recruited 49 college freshmen who immigrated to Tibet and followed up for 2 years. Control group consisted of 49 gender and age‐matched subjects from sea level. Neuropsychological tests were also conducted to determine whether the subjects' cognitive function had changed in response to chronic HA exposure. Surface‐based cortical and subcortical volumes were calculated from structural magnetic resonance imaging data, and tract‐based spatial statistics (TBSS) analysis of white matter (WM) fractional anisotropy (FA) based on diffusion weighted images were performed. Compared to healthy controls, the high‐altitude exposed individuals showed significantly lower accuracy and longer reaction times in memory tests. Significantly decreased gray matter volume in the caudate region and significant FA changes in multiple WM tracts were observed for HA immigrants. Furthermore, differences in subcortical volume and WM integration were found to be significantly correlated with the cognitive changes after 2 years' HA exposure. Cognitive functions such as working memory and psychomotor function were found to be impaired during chronic HA. Differences of brain subcortical volumes and WM integration between HA and sea‐level participants indicated potential impairments in the brain structural modifications and microstructural integrity of WM tracts after HA exposure.