Faculty Bibliography

BACKGROUND:This study primarily aimed to explore the etiology of the phenotypic relationships between personality traits and executive functions. We assessed common genetic and environmental sources of variance in these phenomena by examining different dimensions of the Five Factor Model (FFM) and executive function factors. An additional research question focused on whether specific facets within the FFM share a greater genetic overlap with executive functions compared to broader personality dimensions. METHODS:The NEO-PI-R, the Wisconsin Card Sorting Test, the Trail Making Test, and verbal fluency tests were applied to a sample of 468 twins from the Serbian Twin Advanced Registry (153 monozygotic twin pairs). RESULTS:Several facets from all domains had significant genetic associations with executive functions, with Ideas and Values showing the highest positive correlations, and Order and Vulnerability showing the highest negative genetic correlations. Most phenotypic associations between the two domains of individual differences were almost entirely explained by shared genetic influences. CONCLUSIONS:These findings underscore the importance of examining personality traits at the facet level, as facet-level analysis provides more detailed insights into the relationship between personality and executive functions than broader personality dimensions. The results emphasize the role of shared genetic influences in shaping both personality and executive abilities, suggesting that future research should investigate the underlying neural mechanisms driving these associations.

BACKGROUND/UNASSIGNED:DNA methylation (DNAm) and the personality traits outlined in the NEO-PI-R model through an epigenetic study of monozygotic twins. DNAm, a critical epigenetic mechanism, regulates gene expression and has been linked to various biological processes and disorders. By leveraging the genetic similarities of monozygotic twins, this research explores how epigenetic variations influenced by environmental factors correlate with personality differences. METHODS/UNASSIGNED:) gene, focusing on its role in dopamine metabolism, which is hypothesized to influence personality traits through the dopaminergic system. DNAm status in the MB-COMT promoter region was examined to determine its association with personality facets. RESULTS/UNASSIGNED:DNAm patterns and personality traits. Specific methylation patterns at different CpG sites were linked to varying expressions of traits such as impulsivity and aggression, highlighting the nuanced impact of epigenetics on personality. CONCLUSION/UNASSIGNED:This study underscores the potential of integrating genetic, epigenetic, and environmental data to enhance our understanding of personality formation. The results contribute to a broader understanding of how genetic predispositions shaped by environmental factors manifest in complex trait differences, paving the way for future research in genetic psychiatry and personalized medicine.

Epigenetic modifications of the membrane bound catechol-O-methyltransferase (MB-COMT) gene may affect the enzymatic degradation of dopamine, and consequently, human behavior. This study investigated the association between membrane bound catechol-O-methyltransferase DNA methylation (DNAm) differences in 92 monozygotic (MZ) twins with phenotypic manifestations of cognitive, behavioral, and personality indicators associated with reward-related behaviors and lack of control. We used pyrosequencing to determine DNAm of the regulatory region of membrane bound catechol-O-methyltransferase in saliva DNA. Results of intrapair differences in the percentage of membrane bound catechol-O-methyltransferase DNAm at each of five CpG sites show that there are associations between phenotypic indicators of lack of control and membrane bound catechol-O-methyltransferase DNAm differences on CpG1, CpG2 and CpG4, suggesting the common epigenetic patterns for personality traits, cognitive functions, and risk behaviors.

OBJECTIVE:The main goal of this study was to explore the latent structure and genetic basis of cognitive processes involved in the Wisconsin Card Sorting Task (WCST) within phenotypic, behavioral genetic, and molecular genetic research paradigms. METHOD/METHODS:The sample used in phenotypic and behavioral genetic analyses comprised 468 twins (154 monozygotic and 80 dizygotic twin pairs), while molecular genetic analyses were performed on 404 twins from the same sample. The zygosity of most twin pairs (96.8%) was determined via deoxyribonucleic acid (DNA) analysis of buccal swabs. Trained researchers administered the Wisconsin Card Sorting Test (WCST; Heaton et al., 1993) to the entire sample. RESULTS:Met- genotype. CONCLUSIONS:Met + genotype showed significant main effects on different WCST measures. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Two studies examined genetic and environmental influences on traits proposed by the revised Reinforcement Sensitivity Theory (rRST) of personality. Both quantitative and molecular behavioral genetic methods were applied considering the effects of COMT, DRD2, HTR1A and TPH2 single nucleotide polymorphisms (SNPs). Study one included 274 monozygotic and 154 dizygotic twins for the quantitative behavioral study; and in study two there were 431 twins for the molecular genetic study. The Reinforcement Sensitivity Questionnaire was used to assess basic personality traits defined by the rRST. Univariate biometric modeling suggested that genetic influences accounted for 34-44% of variance of Behavioral Approach System (BAS), Behavioral Inhibition System (BIS) and Fight-Fligh-Freeze System. Molecular genetic analyses proposed the significant main effect of COMT SNP on the BAS and TPH2 SNP on the BIS, and pointed out epistatic effects of COMT x DRD2 on BAS and HTR1A x TPH2 on Fight. Results demonstrated substantial heritability for all rRST constructs, as well as for differences in the molecular genetic basis of both approach-related and avoidance-related dimensions.

The main aim of this study was to explore the etiology of relations between general cognitive ability (g) and different hierarchical phenotypic levels of the Five Factor Model (FFM), including the General Factor of Personality (GFP), the Big Two, the five domains of the FFM, and their 30 facets. The second aim was to detect personality facets that contribute to the prediction of general intelligence. The sample consisted of 424 young adult twins (134 pairs of monozygotic twins) on whom the NEO-PI-R and Advanced Progressive Matrices were administered. The results did not support hierarchical solutions above the FFM. Thus, five-domain and facet level of personality were analyzed, showing that only Openness and Neuroticism had significant genetic or environmental correlations with intelligence. The several facets from all domains had significant associations, among which Ideas and Positive Emotions showed the highest positive correlations, while Order and Modesty showed the highest negative genetic correlations with intelligence. Furthermore, seven facets significantly predicted g factor (35%), with higher genetic (0.52) than environmental (0.13) correlations with intelligence. The results reveal the common genetic basis of narrow traits and intelligence, highlighting the importance of specific traits in the explanation of general cognitive abilities.

The aim of this study was to explore genetic and environmental contributions to laboratory-induced aggressive behavior. On a sample of 478 adult twins (316 monozygotic), the Competitive Reaction Time Task was used for aggression induction. The results showed that the initial, basic level of aggression could be explained by both shared (45%) and nonshared environmental factors (55%), while only nonshared environmental factors (100%) had a significant influence on changes in aggression as provocation increased. Genetic factors had no influence on laboratory-induced aggression. The results highlight the importance of environmental factors in shaping situation-specific aggressive responses to provocation.

The first aim of this study was to explore the aetiology of phenotypic relationships between different measures of executive functions. The second objective was to examine sources of the covariation between different measures of executive functions and the measure of general cognitive ability. The study sample consisted of 468 twins (154 pairs of monozygotic twins and 80 pairs of dizygotic twins) of the same and different gender who grew up together. Executive functions were evaluated by the Wisconsin Card Sorting Test, the Trail Making Test "“ form B, and verbal fluency tests. Raven's Advanced Progressive Matrices were used as a measure of general cognitive ability. The study results suggest a primarily genetic origin of the mutual covariation of different executive measures and their covariation with the general cognitive ability construct. While the shared genetic variance primarily lies in the bases of similarity/unity of the used cognitive measures, their particularity/difference is determined by a specific unshared environment. The obtained result on the presence of a single general genetic factor, which can be singled out in the case of different executive measures, at least partially speaks in favor of the thesis about the unity of various executive measures and the existence of a common basic ability. Together with the specific unshared environment, the specific genetic influence speaks in favor of a difference between each of the individual measures.

This study examines cultural differences in genetic and environmental influences on Five-Factor Model (FFM) across Croatian, German and Serbian cultures. Participants were 1021 monozygotic and 722 dizygotic twin pairs and NEO Five-Factor Inventory"“ NEO-FFI is used to assess FFM personality traits. Results show a similar pattern of genetic and environmental contribution to the variance of all FFM dimensions, indicating that culture has no significant effect on the genetic and environmental variance of personality traits. The best fitted common factor - common AE pathway models show that FFM dimensions are accounted for by the common latent factor. Although FFM dimensions clearly share some common sources of variance, the effects of specific genetic and environmental factors are more pronounced than common ones. Different patterns of genetic and environmental correlations across three samples may reflect the way that the synergy of personality traits responds to the specificities of a particular culture, as well as possible subtle differences in item translation, testing conditions, and measurement error.

STUDY DESIGN/METHODS:This is a retrospective analysis of electromyographic (EMG) stimulation thresholds of 64 cortical bone trajectory (CBT) screws. OBJECTIVE:The authors seek to determine whether recordings below stimulation threshold correlate with CBT screw pedicle breach on computed tomographic imaging, and to explore which specific nerve roots are most at risk with this new trajectory. SUMMARY OF BACKGROUND DATA/BACKGROUND:Intraoperative EMG monitoring has been utilized to verify accurate placement of pedicle screws. Although CBT screws are becoming increasingly popular, to the authors' knowledge there are no existing evaluations of the accuracy of intraoperative triggered EMG (tEMG) monitoring in this trajectory. MATERIALS AND METHODS/METHODS:Retrospective analysis of EMG stimulation thresholds of 64 CBT screws placed in patients at NYU Langone Medical Center from 2015-2017. EMG results including threshold values and muscle group stimulated were correlated with screw positioning determined on postoperative or intraoperative computed tomographic imaging. RESULTS:In total, 4.7% of EMG threshold values indicated true breach, 1.6% were falsely positive for breach, 76.5% showed true absence of breach, 17.1% failed to reveal a present breach though 0% of medial breaches were undetected. L4 screws showed tEMG responses from adductor longus in 22%, L5 screws, from rectus femoris in 16.7%, and S1 screws from tibialis anterior in 50%. CONCLUSIONS:tEMG testing is effective for medial breaches in CBT screws. In addition, there is evidence that bicortical placement of these screws causes lower stimulation values due to distal breach. Importantly, it seems that this is due in part to stimulation of the exiting nerve root at the level above.