Gradual growth versus shape invariance in perceptual decision making

A dominant theme in modeling human perceptual judgments is that sensory neural activity is summed or integrated until a critical bound is reached. Such models predict that, in general, the shape of response time distributions change across conditions, although in practice, this shape change may be subtle. An alternative view is that response time distributions are shape invariant across conditions or groups. Shape invariance is predicted by some race models in which the first of several parallel fibers to communicate the signal determines the response. We competitively assess a specific gradual growth model, the one-bound diffusion model, against a natural shape-invariant competitor: shape invariance in an inverse Gaussian distribution. Assessment of subtle shape change versus shape invariance of response time distributions is aided by a Bayesian approach that allows the pooling of information across multiple participants. We find, conditional on reasonable distributional assumptions, subtle shape changes in response time that are highly concordant with a simple diffusion gradual growth model and discordant with shape invariance.     

Causal Analysis to Enhance Creative Problem-Solving: Performance and Effects on Mental Models

In recent years, it has become apparent that knowledge is a critical component of creative thought. One form of knowledge that might be particularly important to creative thought relies on the mental models people employ to understand novel, ill-defined problems. In this study, undergraduates were given training in the use of causal relationships in applying mental models in creative problem-solving. A pre-post design was used to assess the effects of this training on mental models and creative problem-solving. It was found that causal analysis training resulted in the acquisition of better mental models (in terms of subjective and objective attributes) and better solutions (in terms of quality, originality, and elegance) to problems calling for creative thought among high-ability participants. The implications of these findings for understanding the role of mental models in creative problem-solving are discussed.     

Differences in Rapid Initiation and Termination of Voluntary Postural Sway Associated with Ageing and Falls-Risk

The authors examined differences between young adults (n = 25) and healthy older adults (n = 48) in reaction time and the relations between center of pressure (COP) and center of mass (COM) motions during rapid initiation and termination of voluntary postural sway. Older adults were divided into low and high falls-risk groups based on Physiological Profile Assessment scores of sensorimotor function. Low falls-risk older adults had slower reaction times during anteroposterior sway initiation and decreased COP–COM separation during anteroposterior and medialateral sway initiation and anteroposterior continuous voluntary sway compared with young adults. High falls-risk older adults had slower initiation and termination reaction times in all response directions and decreased COP–COM separation during sway initiation and continuous voluntary sway in the anteroposterior and medialateral directions compared with young adults. Compared with low falls-risk older adults, high falls-risk older adults had slower initiation and termination reaction times in all response directions and decreased COP–COM separation during medialateral continuous voluntary sway. Reaction time and COP–COM measures significantly predicted group status in discriminant models with sensitivities and specificities of 72–100%. Overall, these findings highlight important associations of age-related declines in sensorimotor function related to an increased risk of falling with slower postural reaction time and reduced postural stability.     

Avoiders vs. Amenders: Implications for the investigation of guilt and shame during Toddlerhood?

Abstract

Recent research and theory highlights the distinctive features of shame vs. guilt, as well as the important implications of that distinction for typical and atypical behaviour regulation. Briefly, shame is characterised by withdrawal and hiding from judgemental others, and guilt by making amends–repairing and confessing. The present study was aimed at determining whether a shame-relevant and a guilt-relevant pattern of responses to a standard violation could be distinguished in toddlers.

Two-year-old children participated in a play session, during which a mishap occurred that the children appeared to have caused. Based upon whether or not children avoided the experimenter (E) after the mishap, they were dichotomised into a shame-relevant group of subjects (Avoiders) who avoid E after the mishap, are slow to make reparation, and are slow to tell E about the mishap; and a guilt-relevant group (Amenders) showing the opposite pattern. All guilt-relevant behaviours were greater for Amenders than Avoiders, and all but one shame-relevant behaviour was greater for Avoiders than for Amenders, suggesting coherence in the organisation of responses. Moreover, convergent evidence from a maternal report questionnaire indicated that in non-laboratory settings as well, Amenders manifested greater guilt relative to shame than did Avoiders. Further research is needed to determine developmental antecedents and consequences of the Avoider/Amender dichotomy.     

Clarifying Construct Validity: Definitions,Processes, and Models

Despite definitions in standard sources, personnel managers, psychologists, and psychometricians persistently encounter problems that are best referred to as the ambiguous nature of validity. The purpose of this article is to pro- vide an overview of construct validity and personnel testing, to demonstrate its practical utility, and to clarify with concrete examples certain theories and models, as well as to illustrate the meaning of the terminology used by com- mentators on the topic. A brief historical overview of testing and validation is presented; the progress of construct validity and its acceptance by various sec- tors of society is discussed parsimoniously in the section The Seven Wonders of Personnel Psychology. In the past, personnel psychologists have not done a very good job of understanding the constructs that underlie test perform- ance. Some new approaches can help to correct this. A process should be rou- tinely used on all tests in order to develop an understanding of the constructs that underlie performance on an employment test; only by knowing the cor- rect criterion and method of measuring it can we ascertain the intrinsic valid- ity of our measures.     

Mental rotation of letters,pictures, and three-dimensional objects in German dyslexic children

This study examines mental rotation ability in children with developmental dyslexia. Prior investigations have yielded equivocal results that might be due to differences in stimulus material and testing formats employed. Whereas some investigators found dyslexic readers to be impaired in mental rotation, others did not report any performance differences or even superior spatial performance for dyslexia. Here, we report a comparison of mental rotation for letters, three-dimensional figures sensu Shepard and Metzler, and colored pictures of animals or humans in second-grade German dyslexic readers. Findings indicate that dyslexic readers are impaired in mental rotation for all three kinds of stimuli. Effects of general intelligence were controlled. Furthermore, dyslexic children were deficient in other spatial abilities like identifying letters or forms among distracters. These results are discussed with respect to the hypotheses of a developmental dysfunction of the parietal cortex or a subtle anomaly in cerebellar function in dyslexic readers.     

How many notions of necessity?

Evans distinguishes between superficial necessity and deep necessity in his analysis of the contingent a priori. The distinction between these two notions of necessity is formalized by Davies and Humberstone through the addition of the operator Fixedly to Actuality Modal Logic (AML, S5A), where deep necessity is represented by the combination Fixedly Actually. Wehmeier’s Subjunctive Modal Logic (SML) provides an extension of the expressive capacity of ordinary modal predicate logic alternative to AML. I add Fixedly to SML and show that in the system SML with Fixedly the distinction between deep and superficial necessity disappears. I conclude that the existence of the distinction between deep and superficial necessity, as well as the existence of the contingent a priori, cannot be asserted independently of the choice of background logic.     

Adolescent intelligence and socio-economic wealth independently predict adult marital and reproductive behavior

Counter-intuitively, sociobiological and evolutionary theories predict a negative relationship between g and reproduction when applied to modern humans. Although existing research has documented this dysgenic trend, the association between g and socio-economic factors presents a confound that has not systematically been addressed in prior research. Based on a sample of 325,252 individuals drawn from the nationally representative Project Talent database, we examined the unique effects of g and socio-economic wealth, assessed in adolescence, on marital and reproductive behavior over the next 11 years. Results show that both g and socio-economic wealth have unique, independent negative effects on marital and reproductive behavior such that individuals of higher intelligence and higher wealth delay marriage and reproductive longer than those of lower intelligence and wealth. The effect of g was slightly stronger than that of wealth, though for both variables much of their influence was mediated by educational attainment. Consistent with sociobiological theory, these dysgenic effects were stronger among females than males.     

It Works Both Ways: The Relationship Between Exposure to Sexual Content in the Media and Adolescent Sexual Behavior

Using a longitudinal Web-based survey of adolescents 14–16 years of age, we estimate regression models where self-reported sexual behavior and content analytic-based exposure to sex in the media are related cross-sectionally and longitudinally. We find evidence for both cross-sectional nonrecursive and prospective longitudinal relationships even after adjusting for both established predictors of sexual behavior (e.g., physical development, having a romantic partner, parental monitoring, peer and parental norms, respondent's age) and of exposure to sexual media content (e.g., time the respondent goes to bed, extracurricular activities, television in the bedroom, total time spent with television, music, video games, and magazines). Sexually active adolescents are more likely to expose themselves to sex in the media and those exposed to sex in the media are more likely to progress in their sexual activity. These findings are consistent with others in the literature that demonstrate a causal effect of exposure to sexual content on sexual behavior but extend established results by also looking at the causal effect of sexual behavior on exposure both cross-sectionally and over time.