Are event-related potentials to dynamic facial expressions of emotion related to individual differences in the accuracy of processing facial expressions and identity?

Despite a wealth of knowledge about the neural mechanisms behind emotional facial expression processing, little is known about how they relate to individual differences in social cognition abilities. We studied individual differences in the event-related potentials (ERPs) elicited by dynamic facial expressions. First, we assessed the latent structure of the ERPs, reflecting structural face processing in the N170, and the allocation of processing resources and reflexive attention to emotionally salient stimuli, in the early posterior negativity (EPN) and the late positive complex (LPC). Then we estimated brain–behavior relationships between the ERP factors and behavioral indicators of facial identity and emotion-processing abilities. Structural models revealed that the participants who formed faster structural representations of neutral faces (i.e., shorter N170 latencies) performed better at face perception (r = –.51) and memory (r = –.42). The N170 amplitude was not related to individual differences in face cognition or emotion processing. The latent EPN factor correlated with emotion perception (r = .47) and memory (r = .32), and also with face perception abilities (r = .41). Interestingly, the latent factor representing the difference in EPN amplitudes between the two neutral control conditions (chewing and blinking movements) also correlated with emotion perception (r = .51), highlighting the importance of tracking facial changes in the perception of emotional facial expressions. The LPC factor for negative expressions correlated with the memory for emotional facial expressions. The links revealed between the latency and strength of activations of brain systems and individual differences in processing socio-emotional information provide new insights into the brain mechanisms involved in social communication.     

Is word perception in a second language more vulnerable than in one's native language? Evidence from brain potentials in a dual task setting

We assessed the effect of additional tasks on language perception in second-language and native speakers. The N400 component of the event-related potential was recorded to spoken nouns that had to be judged for synonymity with a preceding word, while additional choice responses were required to visual stimuli. In both participant groups N400 was delayed as a function of temporal overlap with the additional task. In second-language speakers there was a global delay of N400 independent of additional task load and a decrease of accuracy at highest overlap. These findings are interpreted within a single channel account of language perception.     

Why cast shadows are expendable: insensitivity of human observers and the inherent ambiguity of cast shadows in pictorial art

The kinds of visual cues artists choose to use or not use in their work can offer insight into perceptual processes. On the basis of the observed paucity of the use of cast shadow in pictorial art, we hypothesized that cast shadows might be relatively expendable as pictorial cues. In this study, we investigated two potential reasons for this expendability: first, viewers might be insensitive to much of the information that cast shadows provide; and, second, ambiguities about what is shadow and what is pigment can often be resolved only through motion-something that static media are ill-equipped to deal with. In experiment 1, we used a visual-search paradigm in which viewers had to determine if there were odd cast shadows in sets of 4, 8, 16, and 32 objects. In experiment 2, viewers had to discriminate between shadow/pigment ambiguities in both still and moving images. Our results demonstrate that viewers are neither particularly sensitive to static cast-shadow incongruities, nor are they able to disambiguate cast shadow from pigment without continuous motion information. Taken together, these results may help explain why cast shadows are relatively rare in static pictorial work.     

A longitudinal study of relational aggression, physical aggression, and children's social-psychological adjustment

Although great strides have recently been made in our understanding of relational aggression and its consequences, one significant limitation has been the lack of prospective studies. The present research addressed this issue by identifying and assessing groups of relationally aggressive, physically aggressive, relationally plus physically aggressive (co-morbid), and nonaggressive children during their third grade year in elementary school and then reassessing them a year later, during fourth-grade (N = 224, 113 girls). Two aspects of social-psychological adjustment were assessed during both assessment periods including internalizing difficulties (i.e., withdrawal, depression/anxiety, and somatic complaints) and externalizing problems (i.e., aggressive behavior, delinquency). It was revealed that the strongest predictor of future social-psychological adjustment problems and increases in these problems from third to fourth was the combination of relational and physical aggression. Relational aggression also contributed unique information, relative to physical aggression, in the prediction of future maladjustment. Implications of these findings for future research and prevention efforts, particularly for aggressive girls, are discussed.     

Spatial distortions induced by multiple visual landmarks: how local distortions combine to produce complex distortion patterns

Visual landmarks introduce systematic distortions into spatial short-term memory for single target positions, the exact form of the distortion depending on the spatial layout of the landmarks. In two experiments, we investigated how the combined effect of two landmarks can be predicted from the effects of individual landmarks. Participants used a mouse cursor to reproduce the positions of briefly presented targets in the context of one, the other, or both landmarks. We found that distortions near a landmark are independent of whether another landmark is present, so that remembered space is partitioned into regions dominated by single landmarks. Interestingly, the display midpoint behaves like a "virtual landmark," with its own pattern of distortion. Results are inconsistent with current models of spatial memory distortions but suggest that attentional processes can lead to enhanced fidelity of salient regions in topographical neural networks while also introducing some spatial biases.     

Egocentric and geocentric frames of reference in memory of large-scale space

This experiment investigated the frames of reference used in memory to represent the spatial structure of a large-scale outdoor environment. Participants learned the locations of eight objects in an unfamiliar city park by walking through the park on one of two prescribed paths that encircled a large rectangular building. The aligned path was oriented with the building; the misaligned path was rotated by 45°. Later, participants pointed to target objects from imagined vantage points using their memories. Pointing accuracy was higher in the aligned than in the misaligned path group, and the patterns of results differed: In the aligned condition, accuracy was higher for imagined headings parallel to legs of the path and for an imagined heading oriented toward a nearby lake, a salient landmark. In the misaligned condition, pointing accuracy was highest for the imagined heading oriented toward the lake, and decreased monotonically with angular distance. These results indicated that locations of objects were mentally represented in terms of frames of reference defined by the environment but selected on the basis of egocentric experience.     

Contrasting activity patterns of two related octopus species, Octopus macropus and Octopus vulgaris

Octopus macropus and Octopus vulgaris have overlapping habitats and are exposed to similar temporal changes. Whereas the former species is described as nocturnal in the field, there are conflicting reports about the activity time of the latter one. To compare activity patterns, the authors tested both species in the laboratory. Octopuses were exposed to a light-dark cycle and held under constant dim light for 7 days each. O. macropus showed nocturnal and light-cued activity. According to casual observations, O. vulgaris started out nocturnal but had switched to mostly diurnal when the experiment began. Individual variation of its activity was found. The different activity patterns of O. macropus and O. vulgaris might reflect their lifestyles, the latter species being more generalist.     

Memory for fact, fiction, and misinformation: the Iraq War 2003

Media coverage of the 2003 Iraq War frequently contained corrections and retractions of earlier information. For example, claims that Iraqi forces executed coalition prisoners of war after they surrendered were retracted the day after the claims were made. Similarly, tentative initial reports about the discovery of weapons of mass destruction were all later disconfirmed. We investigated the effects of these retractions and disconfirmations on people's memory for and beliefs about war-related events in two coalition countries (Australia and the United States) and one country that opposed the war (Germany). Participants were queried about (a) true events, (b) events initially presented as fact but subsequently retracted, and (c) fictional events. Participants in the United States did not show sensitivity to the correction of misinformation, whereas participants in Australia and Germany discounted corrected misinformation. Our results are consistent with previous findings in that the differences between samples reflect greater suspicion about the motives underlying the war among people in Australia and Germany than among people in the United States.     

Color naming, lens aging, and grue: what the optics of the aging eye can teach us about color language

Many languages without separate terms for green and blue are or were spoken in locations receiving above-average exposure to ultraviolet-B (UV-B) radiation. It has been proposed that this correlation is caused by premature lens aging. This conclusion was supported by an experiment in which younger observers used the term "blue" less often when they described simulated paint chips filtered through the equivalent of an older observer's lens-removing much short-wavelength light-than when they described the unfiltered versions of the same paint chips. Some stimuli that were called "blue" without simulated aging were called "green" when filtered. However, in the experiment reported here, we found that the proportion of "blue" color-name responses did not differ between younger subjects and older observers with known ocular media optical densities. Color naming for stimuli that were nominally green, blue-green, or blue was virtually identical for older and younger observers who viewed the same (unfiltered) stimuli. Our results are inconsistent with the lens-brunescence hypothesis.     

Functional localization and mechanisms of sequential effects in serial reaction time tasks

Reaction times (RTs) to randomly ordered stimuli are influenced in various ways by the sequence of preceding events. Depending on the response-stimulus interval and stimulus-response compatibility, cost-only or cost-benefit patterns can be observed. In order to localize these effects within the information-processing system, different sequential patterns were induced in overt performance. RTs and amplitude developments of the lateralized readiness potential (LRP) across several trials indicated the accumulation of residual traces as a possible mechanism underlying sequential effects. Analysis of LRP onsets indicated two possible loci of action of such traces. Whereas in motoric stages trace accumulation appeared to produce processing advantages only for continued event repetitions, without corresponding costs for discontinuations, cost-benefit patterns were consistently observed in premotoric stages.