Time preferences in long-tailed macaques (Macaca fascicularis) and humans (Homo sapiens)

Rosati et al. (Curr Biol 17(19):1663–1668, 2007) found in a self-control test in which choice was between a smaller, immediately delivered food and a larger, delayed food, that chimpanzees preferred the larger reward (self-control); humans, however, preferred the smaller reward (impulsivity). They attributed their results to a species difference in self-control. In Experiment 1, monkeys (long-tailed macaques) were exposed to a self-control task in two conditions: where the food was hidden under differently colored bowls and where it was visible. When these two conditions were compared, choice shifted from greater preference for the impulsive alternative in the hidden condition to greater preference for the self-control alternative in the visible condition. Additionally, in both conditions, preference shifted from self-control to impulsivity over sessions. These results were explained in terms of the reversed-contingency effect (a propensity to reach for more over less when rewards are visible) and not to a capacity for self-control. In Experiment 2, humans that demonstrated preference for more over less in choice preferred the impulsive alternative when choice to either alternative was followed by the same intertrial interval—a preference that accelerates trial rates relative to preference of the self-control alternative. When trial rates were equated so that neither choice accelerated session’s end, humans demonstrated self-control. These results suggest that Rosati et al.’s demonstration of impulsivity in humans was due to participants’ desire to minimize session time.     

A cross-linguistic data bank for oral picture naming in Dutch, English, German, French, Italian, Russian, Spanish, and Swedish (PEDOI)

The well established effect of word frequency on adult's picture naming performance is now called into question. This is particularly true for variables which are correlated with frequency, as is the case of age of word acquisition. Since the work of [Carrol and White, 1973] there is growing agreement among researchers to confer an important role in lexical access to this variable. Indeed, it has been shown ( [Hodgson and Ellis, 1998]) that for normal English-speaking adults only the variables 'age-of-acquisition' and 'name agreement' are independent predictors of naming success among the various variables considered. However, when brain-damaged subjects with and without degenerative pathologies are studied, word frequency and word length as well as concept familiarity all give significant effects ( [Hirsh and Funnell, 1995]; [Lambon Ralph et al., 1998]; [Nickels and Howard, 1995]). Finally, it has been suggested that the production of specific error types may be related to such variables. According to [Nickels and Howard, 1994] the production of semantic errors is specifically affected by 'imageability' and in the recent study by [Kremin et al., 2001] 'age of acquisition' predicts (frank) word finding difficulties.     

The EARLY ALLIANCE Prevention Trial: An Integrated Set of Interventions to Promote Competence and Reduce Risk for Conduct Disorder, Substance Abuse, and School Failure

Describes the EARLY ALLIANCE interventions, an integrated set of four programs designed to promote competence and reduce risk for early-onset conduct disorder, substance abuse, and school failure. These interventions are evaluated as part of a prevention trial that begins at school entry and targets child functioning and socializing practices across multiple contexts (school, peer group, family) and multiple domains (affective, social, and achievement coping-competence). The paper presents the conceptual foundation of the four interventions, including a synopsis of the risk and protective factors associated with conduct disorder and related outcomes, and of the coping-competence model driving EARLY ALLIANCE. The developmental rationale, intended impact, and procedures are described for each intervention: a universally administered classroom program and indicated, peer, reading-mentoring, and family programs. Interventions are currently being tested in a prevention trial, which is briefly summarized.     

Impact of the format of user instructions on the handling of a wrist blood pressure monitor

Cognitive Processing - Few studies have focused on procedural documents in the field of home medical devices, although incorrect use and usability problems can have important consequences for the...     

Local Optima in Mixture Modeling

It is common knowledge that mixture models are prone to arrive at locally optimal solutions. Typically, researchers are directed to utilize several random initializations to ensure that the resulting solution is adequate. However, it is unknown what factors contribute to a large number of local optima and whether these coincide with the factors that reduce the accuracy of a mixture model. A real-data illustration and a series of simulations are presented that examine the effect of a variety of data structures on the propensity of local optima and the classification quality of the resulting solution. We show that there is a moderately strong relationship between a solution that has a high proportion of local optima and one that is poorly classified.     

Racial‐ethnic Identity in Context: Examining Mediation of Neighborhood Factors on Children's Academic Adjustment

Research consistently shows that neighborhood socio‐demographic characteristics and residents’ neighborhood perceptions matter for youth well‐being, including a positive sense of racial‐ethnic identity. Although elementary‐school children are likely in the earlier phases of identity formation, the authors examined whether objective and subjective neighborhood characteristics are related to their racial‐ethnic identity and, in turn, their academic adjustment. A diverse sample (30.4% African American, 35.2% White, 12.3% Latino, & 22.0% Other) of 227 children in Grades 2 through 5 were surveyed in afterschool programs. Bivariate correlations showed that youth living in disadvantaged neighborhoods reported more barriers due to their race‐ethnicity, but these barriers were not related to their sense of academic efficacy. Residing in a disadvantaged neighborhood was unrelated to youth's academic self‐efficacy. However, path analyses showed that positive neighborhood perceptions were associated with a stronger sense of race‐ethnicity (i.e., affirmation and belonging), which was in turn related to greater academic efficacy. These results suggest that neighborhood connection provides a source of affirmation and value for young children, helping them to understand who they are as part of a racial‐ethnic group and helping to foster a sense of future achievement opportunities. This study provides additional evidence that along with other important proximal contexts (e.g., family, school), young children's neighborhood context is important for development. Results are discussed to highlight environmental influences on young children's awareness of race‐ethnicity and the implications of the combined impact of neighborhood and racial‐ethnic identity on psychosocial adjustment.     

Complex and subtle structural changes in prefrontal cortex induced by inhibitory control training from childhood to adolescence

A number of training interventions have been designed to improve executive functions and inhibitory control (IC) across the lifespan. Surprisingly, no study has investigated the structural neuroplasticity induced by IC training from childhood to late adolescence, a developmental period characterized by IC efficiency improvement and protracted maturation of prefrontal cortex (PFC) subregions involved in IC. The aim of the present study was to investigate the behavioral and structural changes induced by a 5‐week computerized and adaptive IC training in school‐aged children (10‐year‐olds) and in adolescents (16‐year‐olds). Sixty‐four children and 59 adolescents were randomly assigned to an IC (i.e. Color‐Word Stroop and Stop‐Signal tasks) or an active control (AC) (knowledge‐ and vocabulary‐based tasks) training group. In the pre‐ and posttraining sessions, participants performed the Color‐Word Stroop and Stop‐signal tasks, and an anatomical resonance imaging (MRI) was acquired for each of them. Children's IC efficiency improved from the pre‐ to the posttraining session in boys but not in girls. In adolescents, IC efficiency did not improve after IC training. Similar to the neuroplastic mechanisms observed during brain maturation, we observed IC training‐related changes in cortical thickness and cortical surface area in several PFC subregions (e.g. the pars opercularis, triangularis, and orbitalis of the inferior frontal gyri) that were age‐ and gender‐specific. Because no correction for multiple comparisons was applied, the results of our study provide only preliminary evidence of the complex structural neuroplastic mechanisms at the root of behavioral changes in IC efficiency from pre‐ to posttraining in school‐aged children and adolescents.     

Optimising retention through multiple study opportunities over days: The benefit of an expanding schedule of repetitions

Few studies have investigated how scheduling repeated studies of the same material over several days influences its subsequent retention. The study-phase retrieval hypothesis predicts that, under these circumstances, expanding intervals between repetitions will promote the greatest likelihood that the participant will be reminded of previous occurrences of the item, thus leading to a benefit for subsequent recall. In the present article, participants studied vocabulary pairs that were repeated according to one of three schedules. In the expanding schedule, pairs were presented on days 1, 2 and 13; in the uniform schedule, on days 1, 7 and 13; and in the contracting schedule, on days 1, 12 and 13. Cued-recall was assessed after a retention interval (RI) of 2, 6 or 13 days. Consistent with predictions, the expanding schedule generally led to better performance than the other schedules. However, further analyses suggested that the benefit of an expanding schedule may be greater when the RI is longer.     

La mesure du stress en milieu professionnel avec l’échelle de stress perçu (Perceived Stress Scale): pertinence des versions en dix et quatre items

This article presents the psychometric qualities of the Perceived Stress Scale (Cohen, Kamarck, & Mermelstein, 1983) in ten- and four-item version. Our objectives are to verify if we find the main results of the literature as regards the ten-item version and to observe if the psychometric properties of the four-item version are enough good to use this questionnaire. The population of the study consists of 16853 employees working in French large companies. The analyses concern the structure of questionnaires, internal consistency, capacity to discriminate from groups of persons according to gender, age group and professional status, and the convergent validity of both versions. Our results show that 1) we find the main psychometric characteristics of the ten- item version described in the literature and 2) the four-item version presents qualities enough good to be used in an estimation of the perceived stress.     

Increasing compliance with medical examination requests directed to children with autism: effects of a high-probability request procedure

The purpose of this study was to evaluate the effectiveness of a high-probability (high-p) request sequence as a means of increasing compliance with medical examination tasks. Participants were children who had been diagnosed with autism and who exhibited noncompliance during general medical examinations. The inclusion of the high-p request sequence effectively increased compliance with medical examination tasks. In addition, the procedure was efficient, could be implemented by parents and medical professionals, and did not involve aversive procedures.