On the molecular genetics of flexibility: The case of task-switching,inhibitory control and genetic variants

The adjustment of behavior to changing goals and environmental constraints requires the flexible switching between different task sets. Cognitive flexibility is an endophenotype of executive functioning and is highly heritable, as indicated by twin studies. Individual differences in global flexibility as assessed by reaction-time measurement in a task-switching paradigm were recently related to a single nucleotide polymorphism in the vicinity of the dopamine d2 receptor gene DRD2. In the present study, we assessed whether the DRD2 gene is related to backward inhibition, a control mechanism that contributes to cognitive flexibility by reducing proactive interference by no longer relevant task sets. We found that carriers of the DRD2 A1+ variant who have a lower striatal dopamine d2 receptor density than A1– carriers show a larger backward inhibition effect. This is in line with previous results demonstrating increased behavioral flexibility in carriers of this genetic variant. The discussion relates the present finding to those of previous studies assessing the neurogenetic foundations of inhibitory control.     

The multinomial model of prospective memory: validity of ongoing-task parameters

The objective of this research was to provide additional experimental validation of the multinomial processing tree (MPT) model of event-based prospective memory (Smith & Bayen, 2004). In particular, the parameters that measure trial-type detection in the ongoing task were examined. In three experiments with different response instructions, event-based prospective memory tasks were embedded in ongoing color-matching tasks. The results support the validity of the MPT model, that is, manipulations of ongoing-task difficulty affected the ongoing-task parameters of the MPT model, while leaving the estimates for the prospective and the retrospective components of prospective memory unaffected.     

The Contribution of Neuroimaging to the Study of Language and Aphasia

New structural and functional imaging methods continue to be developed at a rapid pace. In the last 25 years, advanced imaging techniques have provided insights into how language is represented and processed in the brain and how it can be disrupted by damage to, or dysfunction of, various parts of the brain. Imaging studies have also yielded new information regarding how individuals recover language after stroke. We briefly review the strengths and weaknesses of the various radiological methods currently used to study language and aphasia.     

Universal sex differences in the desire for sexual variety: tests from 52 nations, 6 continents,and 13 islands

Evolutionary psychologists have hypothesized that men and women possess both long-term and short-term mating strategies, with men's short-term strategy differentially rooted in the desire for sexual variety. In this article, findings from a cross-cultural survey of 16,288 people across 10 major world regions (including North America, South America, Western Europe, Eastern Europe, Southern Europe, Middle East, Africa, Oceania, South/Southeast Asia, and East Asia) demonstrate that sex differences in the desire for sexual variety are culturally universal throughout these world regions. Sex differences were evident regardless of whether mean, median, distributional, or categorical indexes of sexual differentiation were evaluated. Sex differences were evident regardless of the measures used to evaluate them. Among contemporary theories of human mating, pluralistic approaches that hypothesize sex differences in the evolved design of short-term mating provide the most compelling account of these robust empirical findings.     

Husserl's phenomenological discovery of the natural attitude

In this paper I will give a systematic account of Husserl's notion of the natural attitude in the development from its first presentation in Ideas I (1913) until Husserl's last years. The problem of the natural attitude has to be dealt with on two levels. On the thematic level, it is constituted by the correlation of attitude and horizon, both stemming from Husserl's theory of intentionality. On the methodic level, the natural attitude is constituted by three factors: naturalness, naivety and normality. I shall conclude by sketching out a possible motivation for leaving the natural attitude and thus for entering the sphere of phenomenology.     

Immediate and delayed effects of victim suffering on the attacker's aggression

On the first day of a two-day experiment, male undergraduates were either angered or not, and they were given either high, low, or no metered pain feedback after each shock they supposedly delivered to their previous evaluator for his errors on a learning task. After the learning task the subjects made a number of ratings, including how much they had enjoyed this first session. On the second day, all subjects were simply required to administer shocks to a different person for his mistakes on the same learning task. The angered subjects were more punitive on both days toward both learners than the nonangered men. On the first day the angered men also increased the intensity of the shocks they delivered over trial blocks. Most interestingly, the angered men showed more enjoyment of the first session of the experiment as their victim's pain increased, and this enjoyment rating was related to the angered subjects' level of aggression on the second day of the experiment when they punished an “innocent” victim. The results were interpreted as consistent with the hypothesized reinforcement process which essentially states that signs and/or knowledge of the victim's suffering can reinforce impulsive or angry aggressive behavior.