Possible number systems

Number systems—such as the natural numbers, integers, rationals, reals, or complex numbers—play a foundational role in mathematics, but these systems can present difficulties for students. In the studies reported here, we probed the boundaries of people’s concept of a number system by asking them whether “number lines” of varying shapes qualify as possible number systems. In Experiment 1, participants rated each of a set of number lines as a possible number system, where the number lines differed in their structures (a single straight line, a step-shaped line, a double line, or two branching structures) and in their boundedness (unbounded, bounded below, bounded above, bounded above and below, or circular). Participants also rated each of a group of mathematical properties (e.g., associativity) for its importance to number systems. Relational properties, such as associativity, predicted whether participants believed that particular forms were number systems, as did the forms’ ability to support arithmetic operations, such as addition. In Experiment 2, we asked participants to produce properties that were important for number systems. Relational, operation, and use-based properties from this set again predicted ratings of whether the number lines were possible number systems. In Experiment 3, we found similar results when the number lines indicated the positions of the individual numbers. The results suggest that people believe that number systems should be well-behaved with respect to basic arithmetic operations, and that they reject systems for which these operations produce ambiguous answers. People care much less about whether the systems have particular numbers (e.g., 0) or sets of numbers (e.g., the positives).     

Ensemble coding of faces occurs in children and develops dissociably from coding of individual faces

Ensemble coding allows adults to access useful information about average properties of groups, sometimes even in the absence of detailed representations of individual group members. This form of coding may emerge early in development with initial reports of ensemble coding for simple properties (size, numerosity) in young children and even infants. Here we demonstrate that ensemble coding of faces, which provides information about average properties of social groups, is already present in 6–8‐year‐old children. This access to average information increases with age from 6 to 18 years and its development is dissociable from age‐related improvements in the coding of individual face identities. This dissociation provides the first direct evidence that distinct processes underlie ensemble and individual coding of face identity, evidence that has been lacking from adult studies. More generally, our results add to the emerging evidence for impressively mature sensitivity to statistical properties of the visual environment in children. They indicate that children have access to gist information about social groups that may facilitate adaptive social behaviour.     

Gut interpretations: how difficulties in emotion regulation may help explain the relation of visceral sensitivity with depression and anxiety among young adults with gastrointestinal symptoms

It is widely recognized that abdominal pain and discomfort are common problems in the United States and are often associated with negative quality of life. The prevalence of anxiety/depression elevations and disorders among persons with gastrointestinal disturbances (GI) is estimated to be at least two to three times the rate in the general population. Visceral sensitivity reflects anxiety about GI sensations and its accompanying contexts and often leads to worsening of sensations (e.g. bloating, upset stomach, diarrhea). Among individuals with GI symptoms, visceral sensitivity may be associated with interpreting common sensations as catastrophic which may be related to greater difficulties with emotion dysregulation (e.g. severe anxiety and depression). The current study evaluated the indirect association of visceral sensitivity via emotion dysregulation in relation to depression, anxious arousal, and social anxiety symptoms among 344 young adults with a current history of GI symptoms and problems. Results indicated an indirect effect of visceral sensitivity via emotion dysregulation. These findings provide novel empirical support for the association of visceral sensitivity with emotional distress symptoms among young adults with GI symptoms. Based on the results, targeting emotion dysregulation may be a promising health promotion tactic among young adults with GI symptoms and disorders.     

The physical postures of yoga practices may protect against depressive symptoms,even as life stressors increase: a moderation analysis

Yoga contains sub-components related to its physical postures (asana), breathing methods (pranayama), and meditation (dhyana). To test the hypothesis that specific yoga practices are associated with reduced psychological distress, 186 adults completed questionnaires assessing life stressors, symptom severity, and experience with each of these aspects of yoga. Each yoga sub-component was found to be negatively correlated with psychological distress indices. However, differing patterns of relationship to psychological distress symptoms were found for each yoga sub-component. Experience with asana was negatively correlated with global psychological distress (r = ?.21, p < .01), and symptoms of anxiety (r = ?.18, p = .01) and depression (r = ?.17, p = .02). These relationships remained statistically significant after accounting for variance attributable to Social Readjustment Rating Scale scores (GSI: r = ?.19, p = .01; BSI Anxiety: r = ?.16, p = .04; BSI Depression: r = ?.14, p = .05). By contrast, the correlations between other yoga sub-components and symptom subscales became non-significant after accounting for exposure to life stressors. Moreover, stressful life events moderated the predictive relationship between amount of asana experience and depressive symptoms. Asana was not related to depressive symptoms at low levels of life stressors, but became associated at mean (t[182] = ?2.73, p < .01) and high levels (t[182] = ?3.56, p < .001). Findings suggest asana may possess depressive symptom reduction benefits, particularly as life stressors increase. Additional research is needed to differentiate whether asana has an effect on psychological distress, and to better understand potential psychophysiological mechanisms of action.     

Elaborative feedback: Engaging reward and task-relevant brain regions promotes learning in pseudoword reading aloud

Although much is known about the cognitive and neural basis of establishing letter-sound mappings in learning word forms, relatively little is known about what makes for the most effective feedback during this process. We sought to determine the neural basis by which elaborative feedback (EF), which contains both reward-related and content-specific information, may be more helpful than feedback containing only one kind of information (simple positive feedback, PF) or the other (content feedback, CF) in learning orthography-phonology (spelling-sound) mappings for novel letter strings. Compared to CF, EF activated the ventromedial prefrontal cortex, implicated in reward processing. Compared to PF, EF activated the posterior middle temporal, superior temporal, and supramarginal gyri—regions implicated in orthography-phonology conversion. In the same comparison, EF also activated the left fusiform gyrus/visual word form area—implicated in orthographic processing. Also EF, but not CF or PF, modulated activity in the caudate nucleus. In a postscan questionnaire, EF and PF were rated as more pleasant than CF, suggesting that modulation of the caudate for EF may be due to the coupling of reward and skill content. These findings suggest the enhanced effectiveness of EF may be due to concurrent activation of reward-related and task-relevant brain regions.     

Parameters of Time-out: Research Update and Comparison to Parenting Programs,Books, and Online Recommendations

In reviews published more than 30 years ago, eight parameters important to the use of time-out were identified and available research was summarized. The purpose of the current paper is to provide an updated summary of existing research for each parameter of time-out. Within each parameter, we conducted a thorough review of the published literature and identified all peer-reviewed articles addressing each parameter. We identified and summarized a total of 46 articles across the eight parameters, including 32 not cited in previous reviews. Sufficient findings were available to draw conclusions regarding time-out warning, schedule of time-out, contingent versus noncontingent release, and duration. Tentative conclusions based on only a few studies could be drawn in regard to instructional versus physical administration and verbalized reason for time-out. No conclusions could be drawn regarding time-out signal and specific time-out location. While we know much more today regarding effective implementation of time-out, there is a clear need for further exploration within these identified parameters. In addition to summarizing the literature, we reviewed recommendations made by behavioral parent training programs, parenting books, and parenting Web sites, and compared how well their recommendations matched current research based on the conclusions drawn from our review. We found that parenting sources made strong and specific recommendations on several of the parameters that were either not consistent with available research or simply lacked a sufficient research base.     

Prototypes and same-gender bias in perceptions of hiring discrimination

The present study investigated the relative importance of two explanations behind perceptions of gender discrimination in hiring: prototypes and same-gender bias. According to the prototype explanation, people perceive an event as discrimination to the extent that it fits their preconceptions of typical discrimination. In contrast, the same-gender bias explanation asserts that people more readily detect discrimination toward members of their own gender. In four experiments (n = 797), women and men made considerably stronger discrimination attributions, and were moderately more discouraged from seeking work, when the victim was female rather than male. Further, a series of regressions analyses showed beliefs in discrimination of women to be moderately correlated with discrimination attributions of female victims, but little added explanatory value of participant gender, stigma consciousness, or feminist identification. The results offer strong support for the prototype explanation.     

Mimicry and Investigative Interviewing: Using Deliberate Mimicry to Elicit Information and Cues to Deceit

We examined the effect of deliberate mimicry on eliciting (accurate) information and cues to deceit. Mimicry is considered to facilitate cooperation and compliance in truth tellers, whereas liars are constrained to provide detail. We therefore expected truth tellers to be more detailed than liars, particularly after being mimicked. A total of 165 participants told the truth or lied about a meeting they attended. During the interview, an interviewer mimicked half of the participants. Truth tellers were more detailed than liars, but only in the ‘mimicry present’ condition. Truth tellers also gave more accurate units of information than liars, and the difference was most pronounced in the ‘mimicry present’ condition. Mimicry as a tool for eliciting information and cues to deceit fits well with the emerging ‘interviewing to detect deception’ literature, particularly in the ‘encouraging interviewees to say more’ approach. Copyright © 2015 John Wiley & Sons, Ltd.