Sex differences in parietal lobe morphology: relationship to mental rotation performance

Structural magnetic resonance imaging (MRI) studies of the human brain have reported evidence for sexual dimorphism. In addition to sex differences in overall cerebral volume, differences in the proportion of gray matter (GM) to white matter (WM) volume have been observed, particularly in the parietal lobe. To our knowledge there have been no studies examining the relationship between the sex differences in parietal lobe structure and function. The parietal lobe is thought to be involved in spatial ability, and particularly involved in mental rotation. The purpose of this study is to examine whether sex differences in parietal lobe structure are present, and if present to relate these differences to performance on the mental rotations test (MRT). We found that women had proportionately greater gray matter volume in the parietal lobe compared to men, and this morphologic difference was disadvantageous for women in terms of performance on the MRT. In contrast, we found that men compared to women had proportionately greater parietal lobe surface area, and this morphologic difference was associated with a performance advantage for men on mental rotation. These findings support the possibility that the sexual dimorphism in the structure of the parietal lobe is a neurobiological substrate for the sex difference in performance on the mental rotations test.     

If No Capacities Then No Credible Worlds. But Can Models Reveal Capacities?

This paper argues that even when simple analogue models picture parallel worlds, they generally still serve as isolating tools. But there are serious obstacles that often stop them isolating in just the right way. These are obstacles that face any model that functions as a thought-experiment but they are especially pressing for economic models because of the paucity of economic principles. Because of the paucity of basic principles, economic models are rich in structural assumptions. Without these no interesting conclusions can be drawn. This, however, makes trouble when it comes to exporting conclusions from the model to the world. One uncontroversial constraint on induction from special cases is to beware of extending conclusions to situations that we know are different in relevant respects. In the case of economic models it is clear by inspection that the unrealistic structural assumptions of the model are intensely relevant to the conclusion. Any inductive leap to a real situation seems a bad bet.

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The effects of self-focus on attentional biases in social anxiety:An ERP study

Cognitive theories of social anxiety disorder suggest that biased attention plays a key role in maintaining symptoms. These biases include self-focus and attention to socially threatening stimuli in the environment. The goal of this study was to utilize ERPs that are elicited by a change detection task to examine biases in selective attention (i.e., N2pc) and working memory maintenance (i.e., contralateral delay activity; CDA). Additionally, the effect of self-focus was examined using false heart rate feedback. In support of the manipulation, self-focus cues resulted in greater self-reported self-consciousness and task interference, enhanced anterior P2 amplitude and reduced SPN amplitude. Moreover, P2 amplitude for self-focus cues was correlated with reduced task performance for socially anxious subjects only. The difference in P2 amplitude between self-focus and standard cues was correlated with social anxiety independent of depression. As hypothesized, socially anxious participants (n = 20) showed early selection and maintenance of disgust faces relative to neutral faces as indicated by the N2pc and CDA components. Nonanxious controls (n = 22) did not show these biases. During self-focus cues, controls showed marginal evidence of biased selection for disgust faces, whereas socially anxious subjects showed no bias in this condition. Controls showed an ipsilateral delay activity after being cued to attend to one hemifield. Overall, this study supports early and persistent attentional bias for social threat in socially anxious individuals. Furthermore, self-focus may disrupt these biases. These findings and supplementary data are discussed in light of cognitive models of social anxiety disorder, recent empirical findings, and treatment.     

The Sexual Division of Labor and the Split Paycheck

This essay takes up an apparently minor idea of Susan Moller Okin's Justice, Gender, and the Family—that employers should split the paycheck of wage‐earning husbands between employees and their stay‐at‐home spouses—and suggests that it actually threatens to undermine Okin's entire argument by perpetuating the most central cause of women's inequality by Okin's own account: the sexual division of labor. Recognizing the vital contributions that Okin's seminal work made and the impact that it had on the field of feminist philosophy and political theory, the essay explores the ethical, political, and philosophical problems with this solution to the dire problems of gender inequality and injustice that Okin correctly identifies. The essay suggests that her commitment to liberalism may have resulted in a commitment to an inadequate vision of how to solve the problems of gender inequality, and offers other possibilities that Okin could have pursued instead that sustain her strong commitment to liberalism.     

Ethnic Speech and Ethnic Action as Ethnic Behavior: Part 1. Construction of the Brunel Ethnic Behavior Inventory

This article reports the construction of a new survey—specifically, the Brunel Ethnic Behavior Inventory (BEBI)—designed to measure ethnic speech and ethnic action as separate, yet related, aspects of individuals’ ethnic behavior. Using Tajfel’s social identity theory as a conceptual frame of reference, this study sought an answer to the research question of how many factors actually are measured by the BEBI, and tested the hypothesis that a two-factor model (i.e., Ethnic Speech and Ethnic Action as two correlated factors) would provide significantly better goodness of fit to the correlational data than would a one-factor model (i.e., Ethnic Behavior as one undifferentiated factor). Across one pilot sample (n = 101) and two main samples (n = 120 for Sample 1, n = 148 for Sample 2), the study found that not only did the BEBI measure two factors at most (i.e., Ethnic Speech and Ethnic Action) but, consistent with the hypothesis, the two-factor model yielded better goodness of fit than did the one-factor model. Implications for the conceptualization and measurement of Verkuyten’s “ways of ethnicity” are discussed.     

Anxiety sensitivity taxonicity across gender among youth

The present investigation comparatively evaluated the latent class structure and parameters of anxiety sensitivity (AS) among female and male youth using the Childhood Anxiety Sensitivity Index. Participants were 4462 adolescents (2189 females) in grades 7-12 (M(age)=15.6 years). Consistent with prediction, taxometric analyses indicated the latent structure of AS was taxonic in both males and females, demonstrating the taxonic latent structure of AS is similarly observed across gender. Also consistent with prediction, the base rate of the AS taxon differed between genders -- higher for females (12%) compared to males (7%). These findings are discussed in terms of their implications for the study of AS and panic vulnerability among youth.     

Dysprosodic speech following basal ganglia insult: toward a conceptual framework for the study of the cerebral representation of prosody

Progress in understanding brain/behavior relationships in adult-acquired dysprosody has led to models of cortical hemispheric representation of prosodic processing based on functional (linguistic vs affective) or physical (timing vs pitch) parameters. These explanatory perspectives have not been reconciled, and also a number of neurobehavior syndromes that include dysprosody among their neurological signs have not yet been integrated. In addition to expanding the functional perspective on prosody, some of these syndromes have implicated a significant role of subcortical nuclei in prosodic competence. In this article, two patients with acquired dysprosodic speech following damage to basal ganglia nuclei were evaluated using behavioral, acoustic, cognitive, and radiographic approaches. Selective quantitative measures were performed on each individual's performance to provide detailed verification and clarification of clinical observations, and to test hypotheses regarding prosodic function. These studies, combined with a review of related clinical research findings, exemplify the value of a broader perspective on the neurobehavioral dysfunction underlying acquired adult dysprosodic speech, and lead to a new, proposed conceptual framework for the cerebral representation of prosody.     

Negative affectivity predicts individual differences in decision making for preschoolers

The authors' goal in conducting this study was to explore the association between temperament and future-oriented decision making. Forty-three preschoolers (mean age = 51 months) were given a child variant of the Iowa Gambling Task (IGT) and asked to choose between a deck with higher immediate rewards and a deck with higher future rewards. Children who were higher on the Extraversion/Surgency factor of the Child Behavior Questionnaire chose more frequently from the higher immediate rewards deck early in the game. The externalizing dimension of Negative Affectivity (anger/frustration, soothability and discomfort) made the greatest contribution to prediction of performance in the last block of the game. Children who were more easily frustrated and had difficulty regulating negative emotions chose more from the deck with higher immediate rewards. There was a significant interaction between the externalizing dimension of Negative Affectivity, the internalizing dimension of Negative Affectivity (sadness and fear) and Extraversion/Surgency on the last block. These results suggest a complex association between IGT performance and temperament in preschoolers.     

The automaticity of complex motor skill learning as a function of attentional focus

The present experiment was designed to test the predictions of the constrained-action hypothesis. This hypothesis proposes that when performers utilize an internal focus of attention (focus on their movements) they may actually constrain or interfere with automatic control processes that would normally regulate the movement, whereas an external focus of attention (focus on the movement effect) allows the motor system to more naturally self-organize. To test this hypothesis, a dynamic balance task (stabilometer) was used with participants instructed to adopt either an internal or external focus of attention. Consistent with earlier experiments, the external focus group produced generally smaller balance errors than did the internal focus group and responded at a higher frequency indicating higher confluence between voluntary and reflexive mechanisms. In addition, probe reaction times (RTs) were taken as a measure of the attention demands required under the two attentional focus conditions. Consistent with the hypothesis, the external focus participants demonstrated lower probe RTs than did the internal focus participants, indicating a higher degree of automaticity and less conscious interference in the control processes associated with the balance task.