Increased locus coeruleus tonic activity causes disengagement from a patch-foraging task

High levels of locus coeruleus (LC) tonic activity are associated with distraction and poor performance within a task. Adaptive gain theory (AGT; Aston-Jones & Cohen, 2005) suggests that this may reflect an adaptive function of the LC, encouraging search for more remunerative opportunities in times of low utility. Here, we examine whether stimulating LC tonic activity using designer receptors (DREADDs) promotes searching for better opportunities in a patch-foraging task as the value of a patch diminishes. The task required rats to decide repeatedly whether to exploit an immediate but depleting reward within a patch or to incur the cost of a time delay to travel to a new, fuller patch. Similar to behavior associated with high LC tonic activity in other tasks, we found that stimulating LC tonic activity impaired task performance, resulting in reduced task participation and increased response times and omission rates. However, this was accompanied by a more specific, predicted effect: a significant tendency to leave patches earlier, which was best explained by an increase in decision noise rather than a systematic bias to leave earlier (i.e., at higher values). This effect is consistent with the hypothesis that high LC tonic activity favors disengagement from current behavior, and the pursuit of alternatives, by augmenting processing noise. These results provide direct causal evidence for the relationship between LC tonic activity and flexible task switching proposed by AGT.     

KNOWLEDGE, SPEAKER AND SUBJECT

I contrast two solutions to the lottery paradox concerning knowledge: contextualism and subject-sensitive invariantism. I defend contextualism against an objection that it cannot explain how 'knows' and its cognates function inside propositional attitude reports. I then argue that subject-sensitive invariantism fails to provide a satisfactory resolution of the paradox.     

On the Gendered Nature of Mobile Phone Culture in Israel

Data from surveys and personal interviews were used to analyze gendered patterns and contexts of the mobile phone use of Israelis. The findings suggest that the mobile phone has become an everyday, highly regarded, multipurpose interpersonal communication device rather than a working tool. Both men and women discussed their perceptions of the role of the mobile phone in their lives in quite a traditional gendered manner—activity and technological appropriation for men and dependency and domesticity for women. At the same time, the actual phoning habits and attitudes of users point to a pattern of domestication of the mobile phone and even feminization of its consumption.     

Islamic Female Sexuality and Gender in modern feminist interpretation

Sexuality, gender and patriarchy are modern concepts that Western feminist scholars have unquestioningly utilized in their historical inquiry into women in Islam without ample consideration of periodization or problemization. Within the revelation of the Qur'an, the sexes were gendered in relation to each other in a reflection of their physical and biological complementarity. There was not, however, the construction of sexuality and gendering that is evident in the patriarchal society of the modern world. In this essay, I will attempt to trace the historiographical evolution of female sexuality from the time of the Prophet until the Middle Ages, particularly through the development of the female gendered roles of wifehood and motherhood as found in the Qur'an, hadith and fiqh. Additionally, I will argue that until the present these modern constructs have been taken for granted by postmodern scholarship on the topic across many academic disciplines. This has led to scholarship that superimposes modern conceptual frameworks upon earlier time periods. Although these are modern concepts, they may be aptly applied to discourses evident in the period under review, but they must be properly clarified and situated. Furthermore, I myself will work with these concepts, but I will problematize them to show history as a process through which one can find the precursors for modern sexuality and gender construction.     

Measuring Competence and Dysfunction in Preschool Children: Source Agreement and Component Structure

Agreement between parents and teachers on ratings of three domains of behaviors exhibited by preschool children and the structural relations between these domains were measured. Parents and teachers rated the behaviors of a socioeconomically diverse sample of 610 children; ratings were obtained from parents at three time points and from teachers at two time points. The results indicated little agreement between sources on the ratings of individual child behaviors; however, ratings within a source were stable over time. Principal components analyses of source ratings combined and separately indicated virtually identical and independent three-component solutions comprised of a coping competence, externalizing behavior, and internalizing behavior component. These data suggest that competence and dysfunction develop in response to different contextual demands and underscore the importance of measuring each domain of behavior in clinical and research settings.     

Evidence for a specific cross-modal association deficit in dyslexia: an electrophysiological study of letter-speech sound processing

The phonological deficit theory of dyslexia assumes that degraded speech sound representations might hamper the acquisition of stable letter-speech sound associations necessary for learning to read. However, there is only scarce and mainly indirect evidence for this assumed letter-speech sound association problem. The present study aimed at clarifying the nature and the role of letter-speech sound association problems in dyslexia by analysing event-related potentials (ERP) of 11-year-old dyslexic children to speech sounds in isolation or combined with letters, which were presented either simultaneously with or 200 ms before the speech sounds. Recent studies with normal readers revealed that letters systematically modulated speech sound processing in an early (mismatch negativity or MMN) and late (Late Discriminatory Negativity or LDN) time-window. The amplitude of the MMN and LDN to speech sounds was enhanced when speech sounds were presented with letters. The dyslexic readers in the present study, however, did not exhibit any early influences of letters on speech sounds even after 4 years of reading instruction, indicating no automatic integration of letters and speech sounds. Interestingly, they revealed a systematic late effect of letters on speech sound processing, probably reflecting the mere association of letters and speech sounds. This pattern is strongly divergent from that observed in age-matched normal readers, who showed both early and late effects, but reminiscent of that observed in beginner normal readers in a previous study (Froyen, Bonte, van Atteveldt & Blomert, 2009). The finding that the quality of letter-speech sound processing is directly related to reading fluency urges further research into the role of audiovisual integration in the development of reading failure in dyslexia.     

Religiosity and social welfare: competing influences of cultural conservatism and prosocial value orientation

This research examines the hypothesis that religiosity has two competing psychological influences on the social welfare attitudes of contemporary Americans. On the one hand, religiosity promotes a culturally based conservative identity, which in turn promotes opposition to federal social welfare provision. On the other hand, religiosity promotes a prosocial value orientation, which in turn promotes support of federal social welfare provision. Across two national samples (Ns = 1,513 and 320) and one sample of business employees (N = 710), reliable support for this competing pathways model was obtained. We argue that research testing influences of nonpolitical individual differences on political preferences should consider the possibility of competing influences that are rooted in a combination of personality processes and contextual-discursive surroundings.