Systematic review and meta-analysis of the visual mismatch negativity in schizophrenia.

Mismatch negativity (MMN) is an event-related potential component automatically elicited by events that violate predictions based on prior events. To elicit this component, researchers use stimulus repetition to induce predictions, and the MMN is obtained by subtracting the brain response to rare or unpredicted stimuli from that of frequent stimuli. Under the Predictive Processing framework, one increasingly popular interpretation of the mismatch response postulates that MMN represents a prediction error. In this context, the reduced MMN amplitude to auditory stimuli has been considered a potential biomarker of Schizophrenia, representing a reduced prediction error and the inability to update the mental model of the world based on the sensory signals. It is unclear, however, whether this amplitude reduction is specific for auditory events or if the visual MMN reveals a similar pattern in schizophrenia spectrum disorder. This review and meta-analysis aimed to summarise the available literature on the vMMN in schizophrenia. A systematic literature search resulted in 10 eligible studies that resulted in a combined effect size of g = -.63, CI [-.86, -.41], reflecting lower vMMN amplitudes in patients. These results are in line with the findings in the auditory domain. This component offers certain advantages, such as less susceptibility to overlap with components generated by attentional demands. Future studies should use vMMN to explore abnormalities in the Predictive Processing framework in different stages and groups of the SSD and increase the knowledge in the search for biomarkers in schizophrenia.

Autistic traits and event-related potentials in the general population: A scoping review and meta-analysis.

BACKGROUND: Differences in short and long-latency Event-Related Potentials (ERPs) can help us infer abnormalities in brain processing, considering early and later stages of stimuli processing across tasks and conditions. In autism research, the adult population remains largely understudied compared to samples at early stages of development. In this context, this scoping review briefly summarises what has been described in community and subclinical adult samples of autism. METHOD: The current scoping review and meta-analysis includes 50 records (N = 1652) and comprehensively explores short and long-latency ERP amplitudes and their relationship with autistic traits in adult community samples. RESULTS: This meta-analysis identified, with small to medium effect sizes, distinctive patterns in late ERP amplitudes, indicating enhanced responses to visual stimuli and the opposite patterns to auditory tasks in the included sample. Additionally, a pattern of higher amplitudes was also found for the component P3b in autistic traits. DISCUSSION: Differential effects in visual and auditory domains are explored in light of the predictive processing framework for Autism. It remains possible that different brain mechanisms operate to explain symptoms related with different sensory modalities. P3b is discussed as a possible component of interest in future studies as it revealed a more robust effect for differentiating severity in the expression of autistic traits in adulthood.

Refining the link between psychopathy, antisocial behavior, and empathy: A meta-analytical approach across different conceptual frameworks.

The current meta-analysis includes 477 records (N = 142,692) and comprehensively explores the complex interplay between psychopathy, antisocial behavior, and empathy. First, empathy domains (cognitive and affective) were used to dissociate antisocial behavior from psychopathy. Cognitive empathy was more impaired in antisocial groups (gcognitive = -0.43; gaffective = -0.11), while samples scoring higher in psychopathy displayed larger deficits in affective empathy (gaffective = -0.40; gcognitive = -0.22). Secondly, the specific associations between empathy domains and psychopathy dimensions were evaluated. Most effect sizes pertaining to psychopathy traits closely related to antisocial behavior were mild for both empathy domains (r = -0.03 to -0.21). Callous-affective traits were largely correlated with affective empathy (r = -0.34 to -0.46) and moderately correlated to cognitive empathy (r = -0.26 to -0.27). Diverging results were found for the interpersonal dimension, as boldness-adaptive manifestations were unrelated to cognitive empathy (r = 0.03), while non-adaptive interpersonal traits were negatively associated with both empathy domains (rcognitive = -0.16; raffective = -0.25). Overall, these findings suggest that: (1) psychopathy and antisocial behavior display distinct empathic profiles; (2) psychopathy dimensions are differentially associated with cognitive and affective empathy; (3) the interaction between interpersonal traits and empathy domains is different across the conceptual models of psychopathy.

Abnormal Habituation of the Auditory Event-Related Potential P2 Component in Patients With Schizophrenia.

Auditory event-related potentials (ERP) may serve as diagnostic tools for schizophrenia and inform on the susceptibility for this condition. Particularly, the examination of N1 and P2 components of the auditory ERP may shed light on the impairments of information processing streams in schizophrenia. However, the habituation properties (i.e., decreasing amplitude with the repeated presentation of an auditory stimulus) of these components remain poorly studied compared to other auditory ERPs. Therefore, the current study used a roving paradigm to assess the modulation and habituation of N1 and P2 to simple (pure tones) and complex sounds (human voices and bird songs) in 26 first-episode patients with schizophrenia and 27 healthy participants. To explore the habituation properties of these ERPs, we measured the decrease in amplitude over a train of seven repetitions of the same stimulus (either bird songs or human voices). We observed that, for human voices, N1 and P2 amplitudes decreased linearly from stimulus 1-7, in both groups. Regarding bird songs, only the P2 component showed a decreased amplitude with stimulus presentation, exclusively in the control group. This suggests that patients did not show a fading of neural responses to repeated bird songs, reflecting abnormal habituation to this stimulus. This could reflect the inability to inhibit irrelevant or redundant information at later stages of auditory processing. In turn schizophrenia patients appear to have a preserved auditory processing of human voices.