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.