Abnormalities of the late positive potential during emotional processing in individuals with psychopathic traits: a meta-analysis.

BACKGROUND: Individuals with psychopathic traits display deficits in emotional processing. A key event-related potential component involved in emotional processing is the late positive potential (LPP). In healthy controls, LPP amplitude is greater in response to negative stimuli than to positive or neutral stimuli. In the current study, we aimed to compare LPP amplitudes between individuals with psychopathic traits and control subjects when presented with negative, positive or neutral stimuli. We hypothesized that LPP amplitude evoked by emotional stimuli would be reduced in individuals with psychopathic traits compared to healthy controls. METHODS: After a systematic review of the literature, we conducted a meta-analysis to compare LPP amplitude elicited by emotional stimuli in individuals with psychopathic traits and healthy controls. RESULTS: Individuals with psychopathic traits showed significantly reduced LPP amplitude evoked by negative stimuli (mean effect size = -0.47; 95% CI -0.60 to -0.33; p < 0.005) compared to healthy controls. No significant differences between groups were observed for the processing of positive (mean effect size = -0.15; 95% CI -0.42 to 0.12; p = 0.28) and neutral stimuli (mean effect size = -0.12; 95% CI 0.31 to 0.07; p = 0.21). CONCLUSIONS: Measured by LPP amplitude, individuals with psychopathic traits displayed abnormalities in the processing of emotional stimuli with negative valence whereas processing of stimuli with positive and neutral valence was unchanged as compared with healthy controls.

Eye-tracking evidence of a relationship between attentional bias for emotional faces and depression severity in patients with treatment-resistant depression.

In a retrospective study, 54 patients with treatment-resistant major depressive disorder (TRD) completed a free-viewing task in which they had to freely explore pairs of faces (an emotional face (happy or sad) opposite to a neutral face). Attentional bias to emotional faces was calculated for early and sustained attention. We observed a significant negative correlation between depression severity as measured by the 10-item Montgomery-Åsberg Depression Rating Scale (MADRS) and sustained attention to happy faces. In addition, we observed a positive correlation between depression severity and sustained attention to sad faces. No significant correlation between depression severity and early attention was found for either happy or sad faces. Although conclusions from the current study are limited by the lack of comparison with a control group, the eye-tracking free-viewing task appears to be a relevant, accessible and easy-to-use tool for measuring depression severity through emotional attentional biases in TRD.

Can cognitive neuroscience solve the lab-dilemma by going wild?

Reproducibility, measurability, and refutability are the foundation of the scientific method applied to empirical work. In the study of animal and human behavior, experimental protocols conducted in the lab are the most reliable means by which scientists can operationalize behaviors using controlled and parameterized setups. However, whether observations in the lab fully generalize in the real world remain legitimately disputed. The notion of "experimental design" was originally intended to ensure the generalizability of experimental findings to real-world situations. Experiments in the wild are more frequently explored and significant technological advances have been made allowing mobile neuroimaging. Yet some methodological limitations remain when testing scientific hypotheses in ecological conditions. Herein, we discuss the limitations of inferential processes derive from empirical observations in the wild. The multi-causal property of an ecological situation often lacks controls, and this major concern may prevent the replication and the reliability of behavioral observations. We discuss the epistemological and historical grounds of the induction process for behavioral and cognitive neurosciences and provide some possible heuristics for In situ experimental designs compatible with psychophysics in the wild.

Response-locked component of error monitoring in psychopathy: A systematic review and meta-analysis of error-related negativity/positivity.

Evidence suggests that psychopathic individuals display difficulties to adapt their behavior in accordance with the demands of the environment and show altered performance monitoring. Studies investigating the error-related negativity (ERN) and the error-positivity (Pe) as electrophysiological markers of error monitoring reported contradictory results for this population. To explain these discrepancies, we hypothesized that psychopathy dimensions influence electrophysiological outcomes. We predicted that individuals with impulsive-antisocial features would display abnormal ERN compared to individuals with interpersonal-affective features. A systematic review and meta-analysis of studies investigating ERN and Pe components were conducted. A factorial analysis was undertaken to investigate the role of psychopathy dimensions on ERN and Pe. Compared to controls, psychopathic individuals (n = 940) showed a reduced ERN and Pe amplitude. The factorial analysis indicates a dissociation regarding the construct of psychopathy. The models reported that psychopathic individuals related specifically to the interpersonal-affective dimension displayed normal ERN component and efficient error-monitoring, while psychopathic individuals with a marked impulsive-antisocial dimension display a decreased ERN component and altered performance monitoring.

An EEG investigation of the mechanisms involved in the perception of time when expecting emotional stimuli.

The main goal of the current study was to identify the electrophysiological signatures of the mechanisms involved in the perception of time when expecting positive, neutral or negative stimuli that have equal arousal levels. Participants were asked to compare the duration of time intervals with a 2-sec reference interval. The color of circles marking a given comparison interval signaled the valence of the upcoming stimulus to be presented, each stimulus being drawn from the International Affective Picture System (IAPS). The behavioral data suggest that time distortion can be induced by the expectation of stimuli with different valences and that expecting a negative stimulus leads to an overestimation of time. The electrophysiological data, more specifically the N150, N200, LPP and CNV components, provide evidence of the implication of attentional mechanisms and possibly strategic adjustments of cognitive control for time perception.