Lateralized power spectra of the EEG as an index of visuospatial attention

The electroencephalogram (EEG) was measured in an endogenous orienting paradigm where symbolic cues indicated the likely side of to-be-discriminated targets. Combined results of event-related lateralizations (ERLs) and a newly derived measure from wavelet analyses that we applied on the raw EEG and individual event-related potentials (ERPs), the lateralized power spectra (LPS) and the LPS-ERP, respectively, confirmed the common view that endogenous orienting operates by anterior processes, probably originating from the frontal eye fields, modulating processing in parietal and occipital areas. The LPS data indicated that modulation takes place by increased inhibition of the irrelevant visual field and/or disinhibition of the relevant to-be-attended visual field. Combined use of ERLs, the LPS, and the LPS-ERP indicated that most of the involved processes can be characterized as externally evoked, either or not with clear individual differences as some evoked effects were only visible in the LPS-ERERP, whereas few processes seemed to have an internally induced nature. Use of the LPS and the LPS-ERP may be advantageous as it enables to determine the involvement of internally generated lateralized processes that are not strictly bound to an event like stimulus onset.     

Cognitive Complexity and the Perception of Subtle Racism

The present research demonstrated that cognitive complexity is related to the perception of contemporary, subtle racism. Results indicated that the perception of subtle racism was related to attributional complexity. Further, greater attributional complexity was also related to greater racial complexity, defined as the ability of individuals to overcome the normative assumption that racism is no longer a major social problem in the United States and the extent that individuals think about racism. The relationship between attributional complexity and racial complexity held even when accounting for need for cognition, perspective taking, empathy, and political ideology. Finally, we found that racial complexity mediated the effect of attributional complexity on the perception of subtle racism. Taken together, the results of these three studies contribute a general cognitive mechanism related to the perception of subtle racism; an extension of cognitive and attributional complexity; and a new construct, racial complexity, related to the perception of contemporary, subtle racism.     

Framing Posthumous Organ Donation in Terms of Reciprocity: What Are the Emotional Consequences?

Posthumous organ donation was framed in terms of reciprocity by asking young participants to respond to another person who was or was not registered as an organ donor, while simultaneously manipulating participants' own registration status. Participants were additionally required to adopt the perspective of a potential donor or recipient of organs. The influence of these variables on self-reported anger, fear, pity, guilt, gratitude, and positive self-feelings is systematically described. The results illustrate the relative independence of self-preservational and altruistic motives in organ donation. Practical implications are discussed.     

Stacking fault and dislocation glide on the basal plane of graphite

Generalized stacking-fault energies for the basal plane of graphite are calculated from first principles for slip along two high-symmetry directions. The rhombohedral fault energy compares well with experiment and the anisotropy in behaviour is consistent with observed dislocation network geometry. Utilizing these calculated fault energies within a modified Peierls-Nabarro model, we estimate the barrier for basal dislocation motion based on lattice friction. This is found to be extremely small, from which we conclude that dislocation network interaction and pinning, rather than the Peierls barrier, must determine the practical shear strength of graphite. However, at low dislocation densities or over small crystallite regions, the shear strength should tend to this lower limit. We discuss the relevance of this to the mechanism of lubrication.     

The effects of scenario-based risk information on perceptions of susceptibility to Chlamydia and HIV

Abstract

Objectives: The Self-Report Habit Index (SRHI) was originally reported as one-dimensional; however, habit has been described as characterised by several features. Moreover, one-dimensional models for the SRHI have demonstrated poor fit. Therefore, we aimed to compare multidimensional models with a one-dimensional model in both snacking and physical activity habits, besides examining further instrument characteristics.

Design: A cross-sectional study was conducted with high school and university students (n?=?555).

Main outcome measure: The SRHI adapted for physical activity and for snaking habits was applied at one time point.

Results: Nested models with one factor, two factors and three factors were compared. Next, a hierarchical second-order model was tested, and further validity issues, as well as invariance between habits, were examined. Three-dimensional models represented a better fit for both habits. However, fit was still inadequate in the snacking version. In addition, discriminant validity concerns emerged for the physical activity SRHI. Moreover, invariance between the snacking and the physical activity versions was not confirmed.

Conclusions: Considering the SRHI as composed by the dimensions of ‘lack of awareness’, ‘lack of control’ and ‘history of behavioural repetition’ seems to be more accurate. Nevertheless, our findings suggest that further research is needed.     

Is learning mindfulness associated with improved affect after mindfulness‐based cognitive therapy?

The increased popularity of mindfulness‐based interventions and the growing body of empirical evidence confirming the positive effects of these interventions on well‐being warrant more research to determine if the effects are indeed related to learning mindfulness. The present study extends previous studies, by examining whether and how changes in five core aspects of mindfulness are related to changes in the report of negative and positive affect during an 8‐week course of mindfulness‐based cognitive therapy. The study was performed in 64 individuals from the community with mild to moderate psychological problems. Data were collected by self‐report questionnaires before and directly after the training. Results showed significant decreases in negative affect and increases in positive affect. We also found significant increases in four of the five aspects of mindfulness. Importantly, changes in mindfulness were significantly associated with improved affect, with a distinct pattern found for positive and negative affect. Hereby, our findings extend previous research by showing that learning distinct aspects of mindfulness is differently related to an improved positive affect and a decreased negative affect. Future randomized controlled trials with a larger sample and longer follow‐up period are needed to replicate these findings.     

The puzzle of joking: Disentangling the cognitive and affective components of humorous distraction

Studies in cognitive psychology, marketing, and education indicate that humor distracts attention from non‐humorous information presented at the same time. Two experiments investigated why humor distracts attention. The two basic components of humor comprise (1) incongruency resolution, which poses cognitive demands and (2) positive affect. We disentangled the contributions of cognitive demands and positive affect on distraction based on the notions that (a) both components are possible sources of distraction, and (b) the components were always confounded in previous research. In an evaluative conditioning paradigm, novel products were consistently paired with humorous stimuli, whereas other products were paired with stimuli that were either (1) equally demanding but neutral, (2) equally positive but undemanding, and (3) undemanding and neutral. The results showed that cognitively demanding stimuli distracted attention, irrespective of stimulus positivity. These findings suggest that the cognitive demands of humor, not the positive affect it evokes, underlie the distraction effect. Copyright © 2009 John Wiley & Sons, Ltd.