Empirical evidence suggests that working memory (WM) is closely related to arithmetic performance. WM, which is the ability to monitor and update recent information, underlies various cognitive processes and behaviors including planning, self-regulation, and self-control. However, only a few studies have examined whether WM uniquely explains variance in arithmetic performance when other WM-related domain-general factors are taken into account. In this study, we examined whether WM explains unique variance in arithmetic performance when planning, self-regulation, and self-control are considered as well. We used the Tower of London task as a measure of planning, selfrated reports as a measure of self-regulation and self-control, and WM measures, to test which of these domain-general functions predicts complex multiplication performance. Results showed that planning predicted multiplication accuracy and self-control predicted response time, while WM and self-regulation did not predict complex multiplication performance. Although WM was not a direct predictor of multiplication performance, it possibly exerted its influence as part of planning ability. We suggest that complex multiplication is not predicted by WM per se, but rather by WM-related general cognitive and behavioral factors, namely self-control and the planning component of executive functions.Keywords: arithmetic performance, multiplication, executive functions, planning, working memory, self-regulation, self-control Journal of Numerical Cognition, 2017, Vol. 3(2), 441-467, doi:10.5964/jnc.v3i2.61 Received: 2016-06-06. Accepted: 2017-03-02. Published (VoR): 2017-12-22.Handling Editors: Silke Goebel, University of York, York, United Kingdom; André Knops, Humboldt-Universität Berlin, Berlin, Germany *Corresponding author at: University of Tübingen, Schleichstr. 4, 72076 Tübingen, Germany. E-mail: parvin.nemati@uni-tuebingen.de This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License, CC BY 4.0 (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.People use numerical skills in their everyday life in various situations such as shopping or paying bills at restaurants. About 20% of adults do not achieve basic levels of mathematic competence required for these life skills (Williams, 2003). This mathematical incompetence leads to lower income and less financial security in life (Butterworth, Varma, & Laurillard, 2011;Parsons & Bynner, 2005). Therefore, it is worthwhile to examine the factors that can lead to this incompetence. Two groups of factors that influence mathematical skills have been described in the literature. One group consists of domain-specific factors, such as the approximate number system (e.g., Libertus, Feigenson, & Halberda, 2011; for review see Dietrich, Huber, & Nuerk, 2015) or spatialnumerical associations (e.g., Siegler & Opfer, 2003; but see Cipor...

Background:Identification of children with specific language impairment (SLI) has been viewed as both necessity and challenge. Investigators and clinicians use different tests and measures for this purpose. Some of these tests/measures have good psychometric properties, but it is not sufficient for diagnostic purposes. A diagnostic procedure can be used for identification a specific population with confidence only when its sensitivity and specificity are acceptable. In this study, we searched for tests/measures with predefined sensitivity and specificity for identification of preschool children with SLI from their typically developing peers.Materials and Methods:A computerized search in bibliographic databases from 2000 to August 2015 was performed with the following keywords: “specific language impairment” or SLI” and “primary language impairment” or ‘PLI’ with at least one of the followings: “diagnosis,” “identification,” “accuracy,” “sensitivity,” and “specificity.” In addition, the related citations and reference lists of the selected articles were considered.Results:The results of reviewing 23 included studies show that the index measures used in studies vary in accuracy with the sensitivity ranging from 16% to 100% and the specificity ranging from 14% to 100%.Conclusion:These varieties in sensitivity and specificity of different tests/measures confirm the necessity of attention to the diagnostic power of tests/measures before their use as diagnostic tool. Further, the results indicate there are some promising tests/measures that the available evidence supports their performances in the diagnosis of SLI in preschool-aged children, yet the place of a reference standard for the diagnosis of SLI is vacant among investigations.

Up until now, there has been no study conducted in the field of time perception using very short intervals for a direct comparison between implicit and explicit timing tasks in order to uncover plausibly different underlying mechanisms. Therefore, the aim of this study was to compare human time estimation during implicit and explicit timing tasks with short intervals and the same method. A total of 81 adults were divided into three groups and completed two tasks with one of three different intervals: 500, 1,000, and 2,000 ms. The results revealed an overestimation for all three intervals of the implicit timing task, while participants overestimated 500 ms but underestimated 1,000 and 2,000 ms intervals of the explicit timing task. Moreover, explicit time estimation was more precise than implicit time estimation. We observed the opposite pattern as compared to a few previous studies with long intervals: Short intervals were perceived longer in the implicit timing task as compared to the explicit timing task. We concluded that nontemporal contents represent passing time during the implicit timing task but unlike temporal dimension during the explicit timing task. Therefore, even the same method of measurement led to a different performance in implicit and explicit timing tasks.

Self-regulation is a multidimensional construct that is positively related to academic achievement, such as successful mathematics performance. However, this relation of self-regulation and mathematics performance has mainly been investigated in Western countries with similar cultural contexts, although self-regulation is assumed to be context-sensitive. Therefore, the present study investigated the relation of selfregulation and mathematics performance across two different countries (Germany vs. Iran) in college students. The relation of self-regulation and mathematics performance was expected to be weaker in students of math-related fields, such as Engineering/Informatics, as they are assumed to need less self-regulation to solve the mathematics problems than students of less math-related fields, such as Human Sciences. In total, 122 undergraduate students (German = 60; Iranian = 62) of Human Sciences or Engineering/Informatics participated in this study. We measured selfregulation with the Brief Self-Control Scale (Tangney et al., 2004) and mathematics performance with a complex multiplication test. Results showed that self-regulation did not predict multiplication performance in German or Iranian students, in general. However, when the field of study was considered, self-regulation predicted multiplication performance in the subgroup of German and Iranian students studying Human Sciences within each country. We conclude that cultural context does not seem to play a dominant role in moderating the relation between self-regulation and math performance, however, field of study and more generally familiarity with math may be an important factor to consider in single or cross-cultural studies.

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