Frontal alpha asymmetry and emotional processing in youth with psychopathic traits

Evidence of bottom-up homeostatic modulation induced taVNS during emotional and Go/No-Go tasks

Bilateral transcutaneous auricular vagus nerve stimulation (taVNS) - a non-invasive neuromodulation technique - has been investigated as a safe and feasible technique to treat many neuropsychiatric conditions. such as epilepsy, depression, anxiety, and chronic pain. Our aim is to investigate the effect of taVNS on neurophysiological processes during emotional and Go/No-Go tasks, and changes in frontal alpha asymmetry. We performed a randomized, double-blind, sham-controlled trial with 44 healthy individuals who were allocated into two groups (the active taVNS group and the sham taVNS group). Subjects received one session of taVNS (active or sham) for 60 min. QEEG was recorded before and after the interventions, and the subjects were assessed while exposed to emotional conditions with sad and happy facial expressions, followed by a Go/No-Go trial. The results demonstrated a significant increase in N2 amplitude in the No-Go condition for the active taVNS post-intervention compared to the sham taVNS after adjusting by handedness, mood, and fatigue levels (p = 0.046), significantly reduced ERD during sad conditions after treatment (p = 0.037), and increased frontal alpha asymmetry towards the right frontal hemisphere during the emotional task condition (p = 0.046). Finally, we observed an interesting neural signature in this study that suggests a bottom-up modulation from brainstem/subcortical to cortical areas as characterized by improved lateralization of alpha oscillations towards the frontal right hemisphere, and changes in ERP during emotional and Go/No-Go tasks that suggests a better subcortical response to the tasks. Such bottom-up effects may mediate some of the clinical effects of taVNS.

The relationship between cerebral asymmetry and measures of psychopathy in a non-clinical sample is moderated by both empathic challenge and biological sex

This study investigated the relationship between psychopathy, as assessed by the Levenson Self-Report Psychopathy (LSRP) scale, and cerebral laterality. EEG recordings from frontal cortex (L3 and L4) were taken during both resting conditions and while viewing a video of an emergency field amputation, used as an empathic challenge. The ratio of alpha power from the two recording site was taken as an index of relative activity in the two hemispheres. Eighty three students from the University subject pool were recruited as participants. Male participants had a significantly higher mean LSRP score than did female participants. While LSRP scores were unrelated to cerebral laterality under resting conditions, there was both a significant linear and quadratic negative relationship between LSRP scores and relative left-hemisphere alpha activity. As alpha activity has been reported to be inversely related to brain or mental activity, a negative relationship can be inferred between LSRP scores and right hemisphere neural activity. The female participants had a much stronger quadratic relationship than did the combined sample, while the male sample showed only weak, non-significant relationships. Our data suggest that the relationship between psychopathy and cerebral laterality may be sexually dimorphic.

Proposed Specifiers for Conduct Disorder (PSCD) self-report: Factor structure and validation in a community sample of Belgian youth

The current study examined the psychometric properties of the Proposed Specifiers for Conduct Disorder (PSCD) in a sample of school-attending adolescent Belgian youth (N = 599; M age = 16.51 years, SD = 1.27). Given the recent interest in the PSCD-Short Version (PSCD-SV), this study focused on the 13-item variant of the PSCD. Study findings showed that the PSCD-SV had a hierarchical four-factor structure including the components of grandiose-manipulative (GM), callous-unemotional (CU), daring-impulsive (DI), and conduct disorder (CD). These interrelated factors were found to be internally consistent. The study also showed that the PSCD-SV total score was positively and significantly related to an alternate measure of psychopathy. Further, the study revealed the PSCD-SV was meaningfully related to the five-factor personality domains (i.e., extraversion, conscientiousness, agreeableness) as well as peer functioning and prosocial behavior. Bivariate correlations demonstrated that the dimensions differed in their associations with external correlates (e.g., peer functioning). Regression analyses showed that the GM, CU, and CD components of the PSCD-SV were uniquely associated to externalizing difficulties, whereas only the GM and CU components of the PSCD-SV were associated with low prosocial behaviors. These findings shed light on the conceptual and developmental models for the consideration of psychopathy and conduct problems. The use of the broader psychopathy condition as well as its underpinning dimensions may have important implications for assessment, treatment, and diagnostic manuals. The implications of the current study are further discussed.

Impaired sustained attention in groups at high risk for antisocial personality disorder: A contingent negative variation and standardized low-resolution tomographic analysis study

Objective

This study aimed to explore the characteristics of contingent negative variation (CNV) in groups at high risk for antisocial personality disorder.

Materials and methods

A classic CNV paradigm was used to compare the characteristics of attention maintenance among a group of individuals with conduct disorder (CD group; n = 27), a group of individuals with antisocial personality traits (AP; n = 29), a group of individuals with conduct disorder and antisocial personality traits (CD + AP group; n = 25), and a group of healthy controls (CG group; n = 30), to examine the characteristics of the amplitude and latency of CNV in different processing stages.

Results

Results of the event-related potential analysis were as follows: The mean amplitude analysis between 500 and 1,000 ms revealed that the mean CNV amplitudes in the CD + AP group (-1.388 ± 0.449 μV, P < 0.001) were significantly lower than that in the CG group (-4.937 ± 0.409 μV). The mean amplitude analysis between 1,000 and 1,500 ms revealed that the mean CNV amplitude in the CD + AP group (-0.931 ± 0.646 μV) was significantly lower than that in the CG group (4.809 ± 0.589 μV, P < 0.001). The mean amplitude analysis between 1,500 and 2,000 ms revealed that the mean CNV amplitude in the CG group (3.121 ± 0.725 μV) was significantly higher than that in the CD + AP group (-0.277 ± 0.795 μV, P = 0.012), whereas the mean CNV amplitude in the CD + AP group was not significantly different in the AP group (P = 0.168) and CD group (P > 0.05). Source localization results indicated altered activity in frontal-temporal regions.

Conclusion

The CNV amplitude characteristics in the CD + AP group and AP group were more consistent and fluctuated around the baseline, indicating the absence of attention maintenance resulted in impairments in attention allocation and motor preparation in the CD + AP group and AP group.