Spatial integration under contextual control in a virtual environment

The role of context was examined in the selection and integration of independently learned spatial relationships. Using a dynamic 3D virtual environment, participants learned one spatial relationship between landmarks A and B which was established in one virtual context (e.g., A is left of B) and a different spatial relationship which was established in another virtual context (e.g., A is in front of B). A spatial relationship between B and a goal was then established, using the same landmark-to-goal relationship in each context. When given A in either context at test, participants were more likely to choose a position in expectation of the goal, based on the relationship of A to B previously established in that context. Thus, context can be used to disambiguate conflicting spatial information. This research is discussed in light of Miller and Escobar's (2002) retrieval model.     

Regime Switching State-Space Models Applied to Psychological Processes: Handling Missing Data and Making Inferences

Many psychological processes are characterized by recurrent shifts between distinct regimes or states. Examples that are considered in this paper are the switches between different states associated with premenstrual syndrome, hourly fluctuations in affect during a major depressive episode, and shifts between a “hot hand” and a “cold hand” in a top athlete. We model these processes with the regime switching state-space model proposed by Kim (J. Econom. 60:1–22, 1994), which results in both maximum likelihood estimates for the model parameters and estimates of the latent variables and the discrete states of the process. However, the current algorithm cannot handle missing data, which limits its applicability to psychological data. Moreover, the performance of standard errors for the purpose of making inferences about the parameter estimates is yet unknown. In this paper we modify Kim’s algorithm so it can handle missing data and we perform a simulation study to investigate its performance in (relatively) short time series in cases of different kinds of missing data and in case of complete data. Finally, we apply the regime switching state-space model to the three empirical data sets described above.     

Substance Use Progression from Adolescence to Early Adulthood: Effortful Control in the Context of Friendship Influence and Early-Onset Use

In a sample of 998 ethnically diverse adolescents, a multiagent, multimethod approach to the measurement of adolescent effortful control, adolescent substance use, and friendship influence was used to predict escalations to early-adult tobacco, alcohol, and marijuana use by ages 22-23. Structural equation modeling revealed that adolescent substance use and friends' substance use tended to be highly correlated and together were robust predictors of a problematic pattern of usage for all substances in early adulthood. In addition, the adolescent effortful control construct directly predicted progressions to problematic use of tobacco and marijuana, but not for alcohol. In the alcohol model, effortful control interacted with the construct of substance use lifestyle (based on adolescent alcohol use and friends' substance use) when predicting problematic alcohol use in early adulthood. Results held when comparing across genders and across ethnic groups. These findings emphasize the importance of addressing adolescent self-regulation in interventions designed to treat and prevent early-adult substance abuse.     

Memory aging and brain maintenance

Episodic memory and working memory decline with advancing age. Nevertheless, large-scale population-based studies document well-preserved memory functioning in some older individuals. The influential ‘reserve’ notion holds that individual differences in brain characteristics or in the manner people process tasks allow some individuals to cope better than others with brain pathology and hence show preserved memory performance. Here, we discuss a complementary concept, that of brain maintenance (or relative lack of brain pathology), and argue that it constitutes the primary determinant of successful memory aging. We discuss evidence for brain maintenance at different levels: cellular, neurochemical, gray- and white-matter integrity, and systems-level activation patterns. Various genetic and lifestyle factors support brain maintenance in aging and interventions may be designed to promote maintenance of brain structure and function in late life.     

Reliable facial muscle activation enhances recognizability and credibility of emotional expression

We tested Ekman's (2003) suggestion that movements of a small number of reliable facial muscles are particularly trustworthy cues to experienced emotion because they tend to be difficult to produce voluntarily. On the basis of theoretical predictions, we identified two subsets of facial action units (AUs): reliable AUs and versatile AUs. A survey on the controllability of facial AUs confirmed that reliable AUs indeed seem more difficult to control than versatile AUs, although the distinction between the two sets of AUs should be understood as a difference in degree of controllability rather than a discrete categorization. Professional actors enacted a series of emotional states using method acting techniques, and their facial expressions were rated by independent judges. The effect of the two subsets of AUs (reliable AUs and versatile AUs) on identification of the emotion conveyed, its perceived authenticity, and perceived intensity was investigated. Activation of the reliable AUs had a stronger effect than that of versatile AUs on the identification, perceived authenticity, and perceived intensity of the emotion expressed. We found little evidence, however, for specific links between individual AUs and particular emotion categories. We conclude that reliable AUs may indeed convey trustworthy information about emotional processes but that most of these AUs are likely to be shared by several emotions rather than providing information about specific emotions. This study also suggests that the issue of reliable facial muscles may generalize beyond the Duchenne smile.     

The mental representation of the magnitude of symbolic and nonsymbolic ratios in adults

This study mainly investigated the specificity of the processing of fraction magnitudes. Adults performed a magnitude-estimation task on fractions, the ratios of collections of dots, and the ratios of surface areas. Their performance on fractions was directly compared with that on nonsymbolic ratios. At odds with the hypothesis that the symbolic notation impedes the processing of the ratio magnitudes, the estimates were less variable and more accurate for fractions than for nonsymbolic ratios. This indicates that the symbolic notation activated a more precise mental representation than did the nonsymbolic ratios. This study also showed, for both fractions and the ratios of dot collections, that the larger the components the less precise the mental representation of the magnitude of the ratio. This effect suggests that the mental representation of the magnitude of the ratio was activated from the mental representation of the magnitude of the components and the processing of their numerical relation (indirect access). Finally, because most previous studies of fractions have used a numerical comparison task, we tested whether the mental representation of magnitude activated in the fraction-estimation task could also underlie performance in the fraction-comparison task. The subjective distance between the fractions to be compared was computed from the mean and the variability of the estimates. This distance was the best predictor of the time taken to compare the fractions, suggesting that the same approximate mental representation of the magnitude was activated in both tasks.     

Selective memory retrieval can impair and improve retrieval of other memories

Research from the past decades has shown that retrieval of a specific memory (e.g., retrieving part of a previous vacation) typically attenuates retrieval of other memories (e.g., memories for other details of the event), causing retrieval-induced forgetting. More recently, however, it has been shown that retrieval can both attenuate and aid recall of other memories (K.-H. T. B?uml & A. Samenieh, 2010). To identify the circumstances under which retrieval aids recall, the authors examined retrieval dynamics in listwise directed forgetting, context-dependent forgetting, proactive interference, and in the absence of any induced memory impairment. They found beneficial effects of selective retrieval in listwise directed forgetting and context-dependent forgetting but detrimental effects in all the other conditions. Because context-dependent forgetting and listwise directed forgetting arguably reflect impaired context access, the results suggest that memory retrieval aids recall of memories that are subject to impaired context access but attenuates recall in the absence of such circumstances. The findings are consistent with a 2-factor account of memory retrieval and suggest the existence of 2 faces of memory retrieval.     

Comparability of Self‐Reported Conscientiousness Across 21 Countries

In cross‐national studies, mean levels of self‐reported phenomena are often not congruent with more objective criteria. One prominent explanation for such findings is that people make self‐report judgements in relation to culture‐specific standards (often called the reference group effect), thereby undermining the cross‐cultural comparability of the judgements. We employed a simple method called anchoring vignettes in order to test whether people from 21 different countries have varying standards for Conscientiousness, a Big Five personality trait that has repeatedly shown unexpected nation‐level relationships with external criteria. Participants rated their own Conscientiousness and that of 30 hypothetical persons portrayed in short vignettes. The latter type of ratings was expected to reveal individual differences in standards of Conscientiousness. The vignettes were rated relatively similarly in all countries, suggesting no substantial culture‐related differences in standards for Conscientiousness. Controlling for the small differences in standards did not substantially change the rankings of countries on mean self‐ratings or the predictive validities of these rankings for objective criteria. These findings are not consistent with mean self‐rated Conscientiousness scores being influenced by culture‐specific standards. The technique of anchoring vignettes can be used in various types of studies to assess the potentially confounding effects of reference levels. Copyright © 2011 John Wiley & Sons, Ltd.     

Same same but different!? The differential influence of smilies and emoticons on person perception

Emoticons (ASCII-based character strings) and smilies (pictograms) are widely used in computer-mediated communication as substitutes to compensate for the absence of nonverbal cues. Although their usage has been investigated in numerous studies, it remains open whether they provoke differential effects and whether they lead to person perception patterns similar to what is known from face-to-face interactions. Based on findings from research about person perception and nonverbal communication, we investigated the differential effects of smilies and emoticons with regard to recipients' mood, message evaluation, and person perception in an experimental online study (n=127) with a 2(smiley/emoticon) by 2(positive/negative) between-subjects design (with an additional control condition). Results generally support earlier findings, indicating that the valence of the cue (smiley or emoticon) affects the corresponding impression formation. Further, findings concerning the differential influence of both forms of cues show that there are no differences with regard to message interpretation, whereas smiling smilies have a stronger impact on personal mood than smiling emoticons. The perception of a writer's commitment was only altered by smilies, suggesting that they elicit a stronger impact than emoticons.     

Doing African political philosophy from a universalist perspective

There has been a strong impetus to set the definitional parameters of study in African political philosophy and theory. Many scholars advance the idea of a discipline intended to provide lessons that stem from “original” African moral, ideological, and political traditions. Often, these traditions and their ideas are presented as holding categorical moral substance in so far as they are seen to be specific to a culturally essentialist understanding of “Africa.” In turn, an influential part of the literature estimates the normative value of the intellectual ideas and arguments afforded by a varied historical, socio-cultural and economic African geography by the degree to which, in being tethered to a seemingly homogenous, “culturally African” influence, these ideas can be opposed to a “Western” equivalent. In this article, I argue that the effects on the discipline of attending to, and being defined by, this cultural essentialism are at best unclear, at worst detrimental. I aim to contribute to the side of those who advocate a universalist perspective to the study of African political philosophy and thought, and who argue for jettisoning an unhelpful dichotomy between “West” and “African,” in favour of a methodological, conceptual and historical specificity that allows the discipline to be truly useful to itself and to others.