Catechol-O-methyltransferase Val158Met genotype affects neural correlates of aversive stimuli processing

It was previously shown that variation of the catechol-O-methyltransferase (COMT) gene modulates brain activity during the processing of stimuli with negative valence, but not for pleasant stimuli. Here, we tested whether the COMT genotype also modulates the electrophysiological correlates of emotional processing and explored whether the environmental factor of life stress influences this effect. Using the early posterior negativity (EPN) paradigm, event-related brain potentials were measured in 81 healthy individuals during the processing of pictures that evoked emotions of positive and negative valence. As was hypothesized, the COMT genotype affected the EPN amplitudes for unpleasant stimuli, but not for pleasant ones. Specifically, Met/Met carriers respond more sensitively to unpleasant stimuli, as compared with Val/Val carriers. We did not find evidence that life stress moderates the effect of the COMT genotype on emotional stimuli processing.     

Timing accuracy of Web experiments: A case study using the WebExp software package

Although Internet-based experiments are gaining in popularity, most studies rely on directly evaluating participants’ responses rather than response times. In the present article, we present two experiments that demonstrate the feasibility of collecting response latency data over the World-Wide Web using WebExp—a software package designed to run psychological experiments over the Internet. Experiment 1 uses WebExp to collect measurements for known time intervals (generated using keyboard repetition). The resulting measurements are found to be accurate across platforms and load conditions. In Experiment 2, we use WebExp to replicate a lab-based self-paced reading study from the psycholinguistic literature. The data of the Web-based replication correlate significantly with those of the original study and show the same main effects and interactions. We conclude that WebExp can be used to obtain reliable response time data, at least for the self-paced reading paradigm.     

Predicting future affective states: How ease of retrieval and faith in intuition moderate the impact of activated content

Prior research suggests that duration bias—the tendency to overestimate the duration of affective states—is due to individuals' inordinate focus on event‐related information. We propose that the impact of focusing on event‐related (vs. unrelated) content is moderated by the ease with which the information is brought to mind. In the present experiment, participants thought about a possible future negative event and made affective forecasts after retrieving either few or many aspects in their life that would be affected (or unaffected) by the event. Participants estimated longer duration of affective consequences when they retrieved event‐related rather than event‐unrelated information. However, this effect was restricted to conditions where the respective information was brought to mind easily. Importantly, results also revealed that individual differences in faith in intuition moderated the effect of manipulated ease of retrieval. Copyright © 2008 John Wiley & Sons, Ltd.     

Adaptive Individual Differences

Individuals differ in innumerable ways, some adaptive, some maladaptive, and some neutral. Personality theories, we argue, can profit from distinguishing among these importantly different types of individual variation. This article outlines a taxonomy of origins of individual differences— environmental sources of adaptive differences (e.g., early environmental calibration), heritable sources of adaptive differences (e.g., adaptive self-assessment of heritable qualities), nonadaptive sources of individual differences (e.g., incidental by-products of adaptive variation), and maladaptive sources of individual differences (e.g., epigenetic trauma). The second section outlines empirical procedures for confirming or falsifying the differing conceptions of individual differences, with a special focus on empirically distinguishing adaptive individual differences from those that are maladaptive or nonadaptive. The final section highlights the importance of individual differences for solving social adaptive problems.