Visual P300 and the self-directedness scale of the Temperament and Character Inventory

Examining impulsivity and risky decision making among school youth in balloon analogue risk task

BACKGROUND

Impulsivity trait as a risk factor which typically displayed in risk decision among school youth. This study aims to examine behavioral and cognitive problems of risky decision among Chinese young people aged 15-25 years. The balloon analogue risk task (BART) and event-related potential (ERP) were combine used to explore the neural mechanism of risky decision process whether infected by impulsivity trait.

METHODS

A total of 31 subjects were included, including 16 experimental subjects with risk behavior (RS), and 15 health control subjects with non-risk behavior (HC). BART were used to measure risk-taking propensity and ERP were to record in real time. RS vs. HC were compared to explain the relationship between impulsivity and risky decision.

RESULTS

Behavioral data in BART task shown that the RS subjects tended to make risky decisions. ERP results illustrate that P300 in RS subjects is more significant positive-going than HC that means dysfunction of cognitive control, and FRN in RS subjects is more negative-going than HC in negative feedback condition, which means individual with high impulsive would be more sensitive to unexpected outcome.

CONCLUSIONS

Impulsiveness is a risk factor for school adolescent, because RS subjects performed more risky decision than control group, the evidence indicate that individual with high impulsiveness would lead to be less sensitive to harmful consequences and more inclination to immediate rewards. Therefore, the inclination of risk taking can be powerfully informed by different levels of impulsiveness.

Self-directedness and the susceptibility to distraction by saliency

People with low Self-directedness (SD) tend to explain their behaviour as being significantly influenced by events in the external environment. One important dimension of external cues is their level of salience: highly salient external stimuli are more likely to capture attention, even when such stimuli are not relevant to goals. We examined whether adults reporting low SD would exhibit greater susceptibility to distraction by highly salient external stimuli. Fifty-four (42 males) subjects completed the Attention Modulation by Salience Task (AMST) measuring reaction times to early- or late-onset auditory stimuli in the presence of high- or low-salience visual distractors. SD was assessed via self-report, and analyses tested the relationship between SD and performance on the AMST. Results showed a slowed early response to auditory cues during high salience compared to low salience. Indeed, individuals reporting low SD showed stronger salience interference, suggesting that external causality attribution is accompanied by a subconscious perceptual deficit.

Temperament and character personality profile in relation to suicide attempts in patients with schizophrenia

INTRODUCTION

Schizophrenia is associated with a significant risk of suicide, and suicide still remains one of the main causes of death in schizophrenic patients. Beside classic risk factors for suicidality, temperament and character traits have been researched and considered as risk factors for suicidal behavior in recent years.

METHOD

Subjects were 94 patients with schizophrenia who were under treatment. All patients were in a stable phase of the illness. Patients with lifetime suicide attempt (n = 46) and without suicidal attempt (n = 48) were compared with each other in terms of temperament and character traits by using the Temperament and Character Inventory.

RESULTS

Harm avoidance and persistence scores were higher in suicidal schizophrenic patients compared with nonsuicidal schizophrenic patients. The scores of self-directedness and cooperativeness were lower in suicidal schizophrenic patients compared with nonsuicidal schizophrenic patients. These 4 variables remained significant predictors of lifetime suicidal attempts in a logistic regression model.

CONCLUSION

To the best of our knowledge, the present study is the first that specifically compares schizophrenic patients with and without suicidal behavior by the Cloninger temperament and character model. Our data indicate that schizophrenic patients will show a greater risk for suicide according to certain personality configurations. However, to establish causal relationships between personality and suicidality in schizophrenia, longitudinal studies are warranted within a multifactorial interactive framework of biologic and clinical variables.

Temperament and character personality profile in relation to suicidal ideation and suicide attempts in major depressed patients

To prevent suicidal behaviour, it is important to better understand those personality traits associated with suicidal ideation and suicide attempts. A sample of 394 consecutive major depressed outpatients admitted to Bonn University Hospital was subdivided into three groups: Lifetime suicide attempters (N=32; 8.1%), suicide ideators (N=133) and patients without suicide ideation (N=229). Psychodiagnostic measures embraced the Temperament and Character Inventory (TCI), the Symptom Checklist-90-R and the Hamilton Depression Rating Scale. Suicide attempters and ideators showed higher scores on emotional distress and depression. Analysis of covariance (covariates: age, gender, depression) revealed that suicide attempters score higher on the temperament dimension harm avoidance compared with non-attempters. Suicide ideators could be distinguished from non-ideators by character dimensions in terms of lower self-directedness and higher self-transcendence. Our findings suggest that high harm avoidance is a personality trait associated with suicide attempt in major depression, whereas low self-directedness and high self-transcendence are related to suicidal ideation. As temperament dimensions represent the "emotional core" and character dimensions the "cognitive core" of personality, we discuss whether Cloninger's psychobiological model might be helpful to distinguish between non-suicide ideators, patients who do think about suicide, and patients initiating suicidal behaviour.

D2 dopamine receptor (DRD2) gene, P300, and personality in children of alcoholics

The D2 dopamine receptor (DRD2) gene has been associated with alcoholism and other drug use disorders. Reduced P300 amplitude has been noted in individuals with psychiatric disorders. Personality variables are also associated with reduced P300 amplitude. The current study was conducted to determine whether variants of the DRD2 would show differential relationships among P300 amplitude and personality traits. The study consisted of 101 adolescent children of alcoholics; 39 carried the A1(+) genotype (A1A1, A1A2) and 62 carried the A1(-) genotype (A2A2). The A1(+) genotype group had higher IQ and Self-Directedness scores than the A1(-) genotype group. As predicted, the negative relationship between Novelty Seeking and Harm Avoidance was present in A1(-) but not A1(+) participants. Additionally, in A1(+) but not in A1(-) participants, there was a negative relationship between Novelty Seeking and Self-Directedness and a positive relationship between P300 amplitude and Cooperativeness. The results suggest that in adolescent children of alcoholics, dopaminergic genetic determinants are critical modifiers of the relationship between neurocognitive and personality endophenotypes proposed as vulnerability markers for substance use disorders.

BIS/BAS Sensitivity and the P300 Event-Related Brain Potential

Abstract. Both a reduced amplitude of the P300 event-related potential component and a highly impulsive personality are known to be strong predictive markers for substance abuse and related psychiatric disorders. Because of this common link to externalizing psychopathology, a significant negative association between the P300 amplitude and personality measures related to behavioral disinhibition is expected. The present study investigated correlations between the visual P300 amplitude and the personality dimensions of Behavioral Approach System (BAS) sensitivity and Behavioral Inhibition System (BIS) sensitivity among healthy subjects (N = 44; mean age = 24 ± 4.93 years). To measure BIS and BAS sensitivity the BIS/BAS scales were used. Significant positive correlations were found between BAS sensitivity and P300 amplitude at both anterior and posterior scalp locations above the right hemisphere. There were no significant correlations between P300 amplitude and BIS sensitivity. Results are discussed in light of the rather inconsistent findings from previous studies investigating P300 amplitude and impulsivity-related measures. It is concluded that a P300 amplitude reduction may be regarded as a general, nonspecific marker for psychopathology and psychopathology-prone personality functioning.

The relationship between the biogenetic temperament and character and psychopathology in adolescents

BACKGROUND

This study was conducted to investigate the relationship between patterns of temperament and character and self-reported psychopathology in adolescents from the community.

SAMPLING AND METHODS

The Junior Temperament and Character Inventory (JTCI) and Youth Self-Report (YSR) instruments were administered to 623 Korean middle school students (boys/girls = 331/292; age = 13.3 +/- 0.9 years old). Multiple linear regression analyses were used to evaluate the relationship between temperament and character based on Cloninger's biogenetic theory of personality and youth psychopathology of internalizing and externalizing problems.

RESULTS

Internalizing problems of the YSR (withdrawn, somatic complaint and anxious/depressed scales) were significantly related to high Harm Avoidance and low Reward Dependence (JTCI temperament) and low Self-Directedness and high Self-Transcendence (JTCI character). Externalizing problems of the YSR (delinquency and aggression) were significantly associated with high Novelty Seeking and high Harm Avoidance (JTCI temperament) and low Self-Directedness, low Cooperativeness and high Self-Transcendence (JTCI character).

CONCLUSIONS

Findings of the current study suggest that specific patterns of temperament and character potentially influence adolescents' psychopathology in the community.

Latency of auditory P300 correlates with self-control as measured by the Sixteen Personality Factor Questionnaire

The reception, processing, and storage of information about experience define personality. The present study investigated the relationship between auditory event-related potentials (AERP) and personality traits. The AERP were recorded using a standard auditory oddball paradigm, and personality was evaluated by Cattell's Sixteen Personality Factor Questionnaire (16PF) in 20 healthy young male subjects. The P300 latency was found to be significantly associated with rule consciousness (factor G in the 16PF), perfectionism (factor Q3), and self-control (factor SC): it was negatively correlated with G score (r = -0.56, P = 0.01), Q3 score (r = -0.67, P = 0.001), and SC score (r = -0.65, P = 0.002). Moreover, the P300 amplitude and N100 amplitude were negatively correlated with reasoning (factor B; r = -0.46, P = 0.044; and r = -0.72, P = 0.002, respectively). These results indicate that the personality traits of self-control, perfectionism, high superego, and reasoning are related to information processing in the brain.

Neurobiological dimensional models of personality: a review of the models of Cloninger, Depue, and Siever

Neurobiological dimensional models of personality aim to account for the structure of personality traits and disorders through links to neurotransmitter systems. Three such models are reviewed: those of Cloninger, Depue, and Siever. While these proposals have heuristic value, none of them has obtained strong empirical support. Our current understanding of neurobiology is insufficient to develop a model of personality on this basis. At this point, dimensions of personality should be derived from factor analysis rather than from neurobiological theories.

The genetic and environmental relationship between Cloninger's dimensions of temperament and character

The purpose of this study was to determine whether Cloninger's revised 7-factor model of personality showed incremental validity over his four dimensions of temperament. A sample of 2517 Australian twins aged over 50 between 1993 and 1995 returned completed self-reported measures of Self-directedness, Cooperativeness, and Self-transcendence from Cloninger's Temperament and Character Inventory. Many of these twins had participated in a 1988 study containing Cloninger's temperament measures of Harm Avoidance, Novelty Seeking, Reward Dependence and Persistence. Contrary to theoretical expectations, univariate analyses revealed that familial aggregation for the character dimensions could be entirely explained by additive gene action alone. Although temperament explained 26, 37 and 10% of additive genetic variance in Self-directedness, Cooperativeness and Self-transcendence, respectively, seven genetic factors were required to explain the genetic variance among the TPQ dimensions, and almost all of the non-shared environmental variance was unique to each dimension of character. Our results indicate that the inclusion of all seven dimensions in a taxonomy of personality is warranted.

Genetics of personality: are we making progress?

For centuries, scientists are intrigued by the differences in personality between individuals. As early as in the ancient Greek civilization, people tried to formulate theories to systematize this diversity. With the increased interest in behavior genetics, personality was also considered a challenging phenotype. From the early start, studies suggested a heritable component in personality. After the successes of molecular genetic studies in unraveling the genetic basis of (mostly) monogenic diseases, the focus shifted towards complex traits, including psychiatric disorders. It was observed in several studies that personality measures differed between patients with psychiatric disorders and healthy controls. Therefore, normal personality was considered a viable endophenotype in the search for genes involved in psychiatric disorders such as affective disorders, ADHD and substance dependence. Genes that were to be found in studies on personality could be candidate genes for particular psychiatric disorders. In the course of time, however the study of genes for personality turned out to be at least as hard as the search for genes involved in other complex disorders. In this review, past studies, present problems and future directions concerning the study of personality genetics are discussed.

Electrophysiological correlates of personality dimensions measured by Temperament and Character Inventory

The present exploratory study was attempted to investigate the relationship between components of event-related potential (ERP) and Cloninger's personality dimensions. The ERP was measured using the auditory oddball paradigm, and personality was evaluated by Temperament and Character Inventory (TCI) in 25 healthy subjects. The results showed that P300 amplitude at Fz was significantly associated with reward dependence, and that P300 latency was positively correlated with persistence, and negatively correlated with novelty seeking. No correlations were found between N100, P200 and personality dimensions. These results indicate that personality dimension is related to information-processing in the brain. The neurobiological and psychological aspects of personality, which may relate to the P300 were considered.

Relationship between personality trait and regional cerebral glucose metabolism assessed with positron emission tomography

There have been no studies systematically investigating relationships between biogenetic temperament dimensions and patterns of brain glucose metabolism. Nineteen healthy subjects were evaluated regarding the biogenetic temperament using Cloninger's Temperament and Character Inventory (TCI). In addition, [18F] fluorodeoxyglucose (FDG) positron emission tomography (PET) was used to measure regional brain glucose metabolism. Voxel-based correlation analysis was used to test correlations between regional brain glucose metabolism and scores on the TCI. We identified that each temperament dimension, such as Novelty Seeking, Harm Avoidance, and Reward Dependence, was significantly correlated with specific brain regions. The majority of correlations were observed in the areas of paralimbic regions and temporal lobes. The current study provides evidence linking each biogenetic temperament dimension with specific brain areas and provides a promising base for future personality research.