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Hostile attribution bias (e.g., tendency to interpret the intention of others as hostile in ambiguous social contexts) has been associated with impulsive aggression in adults, but the results are mixed and the complete sequence of hostile inferential processes leading to aggression has not been investigated yet. The goal of this event-related brain potentials (ERPs) study was to track the neural activity associated with the violation of expectations about hostile versus nonhostile intentions in aggressive and nonaggressive individuals and examine how this neural activity relates to self-reported hostile attributional bias and impulsive aggression in real life. To this end, scenarios with a hostile versus nonhostile social context followed by a character's ambiguous aversive behavior were presented to readers, and ERPs to critical words that specified the hostile versus nonhostile intent behind the behavior were analysed. Thirty-seven aggressive and fifty nonaggressive individuals participated in the study. The presentation of a critical word that violated hostile expectation caused an N400 response that was significantly larger in aggressive than nonaggressive individuals. Results also showed an enhanced late positive potential-like component in aggressive individuals when hostile intention scenarios took place in a nonhostile context, which is associated with impulsive aggression in real life even after having controlled for the effect of self-reported hostile attributional bias. The Hostile Expectancy Violation paradigm evaluated in this study represents a promising tool to investigate the relationship between the online processing of hostile intent in others and impulsive aggression. Aggr. Behav. 43:217-229, 2017. © 2016 Wiley Periodicals, Inc.

Visuospatial attention can be deployed to different locations in space independently of ocular fixation, and studies have shown that event-related potential (ERP) components can effectively index whether such covert visuospatial attention is deployed to the left or right visual field. However, it is not clear whether we may obtain a more precise spatial localization of the focus of attention based on the EEG signals during central fixation. In this study, we used a modified Posner cueing task with an endogenous cue to determine the degree to which information in the EEG signal can be used to track visual spatial attention in presentation sequences lasting 200 ms. We used a machine learning classification method to evaluate how well EEG signals discriminate between four different locations of the focus of attention. We then used a multi-class support vector machine (SVM) and a leave-one-out cross-validation framework to evaluate the decoding accuracy (DA). We found that ERP-based features from occipital and parietal regions showed a statistically significant valid prediction of the location of the focus of visuospatial attention (DA = 57%, p < .001, chance-level 25%). The mean distance between the predicted and the true focus of attention was 0.62 letter positions, which represented a mean error of 0.55 degrees of visual angle. In addition, ERP responses also successfully predicted whether spatial attention was allocated or not to a given location with an accuracy of 79% (p < .001). These findings are discussed in terms of their implications for visuospatial attention decoding and future paths for research are proposed.

The present study examined the joint contribution of shading and stereopsis to the perception of shape convexity-concavity. The stimuli were the images of a synthetic convex 3-D shape seen from viewpoints leading to ambiguity as to its convexity. Illumination came from either above or below, and from either the right or the left, and stimuli were presented dichoptically with normal binocular disparity, reversed disparity, or no disparity. Participants responded "convex" more often when the lighting came from above than from below. Also, participants responded that the shape was convex more often with normal than with zero disparity, and more often with zero disparity than with reversed stereopsis. The effects of lighting direction and display mode were additive--that is, they did not interact. This indicates that shading and stereopsis contribute independently to shape perception.

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