Perception of the stereokinetic illusion by the common marmoset (<Emphasis Type="Italic">Callithrix jacchus</Emphasis>)

Stereokinetic illusions have never been investigated in non-human primates, nor in other mammalian species. These illusions consist in the perception of a 3D solid object when certain 2D stimuli are rotated slowly in the plane perpendicular to the line of sight. The ability to perceive the stereokinetic illusion was investigated in the common marmoset (Callithrix jacchus). Four adult marmosets were trained to discriminate between a solid cylinder and a solid cone for food reward. Once learning criterion was reached, the marmosets were tested in sets of eight probe trials in which the two solid objects used at training were replaced by two rotating 2D stimuli. Only one of these stimuli produced, at least to the human observer, the stereokinetic illusion corresponding to the solid object previously reinforced. At test, the general behaviour and the total time spent by the marmosets observing each stimulus were recorded. The subjects stayed longer near the stimulus producing the stereokinetic illusion corresponding to the solid object reinforced at training than they did near the illusion corresponding to the previously non-rewarded stimulus. Hence, the common marmosets behaved as if they could perceive stereokinetic illusions.     

Infinite Forcing and the Generic Multiverse

Studia Logica - In this article we present a technique for selecting models of set theory that are complete in a model-theoretic sense. Specifically, we will apply Robinson infinite forcing to the...     

The use of spatial and local cues for orientation in domestic chicks (Gallus gallus)

Animal Cognition - Birds have been widely used to study spatial orientation. However, since different birds rely on different types of visual information to find goal locations (such as spatial...     

A longitudinal examination of early communicative development: Evidence from a parent‐report questionnaire

The present research employed a longitudinal design to assess the verbal and non‐verbal communicative abilities of a sample of 104 children, using two different parent‐report instruments: the Questionnaire for Communication and Early Language (QCEL) development at 12, 16, and 20 months, and the Italian adaptation of the MacArthur–Bates Communicative Development Inventories: Words and Gestures at 23 months. The results supported and extended previous data about the validity of the QCEL, by showing that: (1) both verbal and non‐verbal variables predicted the level of language development at 23 months; (2) children classified as at‐risk with the QCEL had reduced vocabulary size and a lower number of sentences at 23 months; (3) early individual differences in the use of words and gestures were associated with later differences in linguistic abilities. It is concluded that the longitudinal use of the QCEL questionnaire can provide useful information about language development.     

Impairment of executive functions in boys with attention deficit/hyperactivity disorder.

The main aim of the present study is to compare the efficiency of executive control processes in 24 boys with attention deficit/hyperactivity disorder (ADHD) and 58 normal controls of similar age (between 8 and 11 years). Three reaction time (RT) paradigms were utilized: a dual task that requires coordination of two tasks responses, a shift task that makes it necessary to disengage attention from one task and engage into another one, and a stimulus-response spatial compatibility task that requires participants to inhibit a prepotent response. Another purpose of the study is to examine whether Barkley's (1997) executive dysfunction or Sergeant et al.'s (1999) resource allocation/arousal model best account for the behavioral deficits associated with ADHD. Examination of raw RT data showed significantly poorer performance in ADHD children with respect to age-matched controls on both the higher-level cognitive functions of executive control and on lower-level abilities (e.g., speed of processing) of all tasks of this study. However, using proportional transformations of raw RT data, we could demonstrate that, in addition to differences in processing speed, also executive control processes were significantly impaired in children with ADHD.     

Rethinking Sikh Nationalism in the Twenty-First Century

This article seeks to draw attention to some of the core issues which beset the study of Sikh nationalism as a coherent phenomenon in an increasingly globalized and socially fragmented world. First, it highlights the importance of revisiting the debate about the community's religious boundaries, arguing that in contrast to the new conventional wisdom informed by poststructuralism, Sikh identity has exhibited a remarkable degree of continuity from the establishment of the Khalsa in comparison with other South Asian religio-political communities. The second key issue highlighted is the role of the Sikh diaspora in the development of Sikh nationalism and statehood. It critically examines the extent to which diaspora may be regarded as an instrument of ‘long-distance’ nationalism. Third, it argues that the existing literature on Sikh nationalism is remarkably community-centric and needs to engage with theories of nationalism. Finally, while acknowledging the cleavages which fragment the Sikh nation, it concludes that Sikh nationalism has been remarkably cohesive.     

$$\mathrm {ZF}$$ ZF Between Classicality and Non-classicality

Studia Logica - We present a generalization of the algebra-valued models of $$\mathrm {ZF}$$ where the axioms of set theory are not necessarily mapped to the top element of an algebra, but may get...     

Virtual morality in the helping professions: Simulated action and resilience

Recent advances in virtual technologies have allowed the investigation of simulated moral actions in aversive moral dilemmas. Previous studies have employed diverse populations to explore these actions, with little research considering the significance of occupation on moral decision-making. For the first time, in this study we have investigated simulated moral actions in virtual reality made by professionally trained paramedics and fire service incident commanders who are frequently faced with and must respond to moral dilemmas. We found that specially trained individuals showed distinct empathic and related personality trait scores and that these declined with years of experience working in the profession. Supporting the theory that these professionals develop resilience in moral conflict, reduced emotional arousal was observed during virtual simulations of a distressing dilemma. Furthermore, trained professionals demonstrated less regret following the execution of a moral action in virtual reality when compared to untrained control populations. We showed that, contrary to previous research, trained individuals made the same moral judgements and moral actions as untrained individuals, though showing less arousal and regret. In the face of increasing concerns regarding empathy decline in health care professionals, we suggest that the nature of this decline is complex and likely reflects the development of a necessary emotional resilience to distressing events.