Impaired acuity of the approximate number system underlies mathematical learning disability (dyscalculia)

Many children have significant mathematical learning disabilities (MLD, or dyscalculia) despite adequate schooling. The current study hypothesizes that MLD partly results from a deficiency in the Approximate Number System (ANS) that supports nonverbal numerical representations across species and throughout development. In this study of 71 ninth graders, it is shown that students with MLD have significantly poorer ANS precision than students in all other mathematics achievement groups (low, typically, and high achieving), as measured by psychophysical assessments of ANS acuity (w) and of the mappings between ANS representations and number words (cv). This relation persists even when controlling for domain-general abilities. Furthermore, this ANS precision does not differentiate low-achieving from typically achieving students, suggesting an ANS deficit that is specific to MLD.     

Conceptions of first‐year university students of the constituents of matter and the notions of acids and bases

Preconceptions of first‐year university students of the constituents of matter and the notions of acids and bases were investigated on a total of 400 students. The procedure used consisted of free interviews, semi‐structured interviews and questionnaires.

It was found that the constituents of matter were well known to students, but that interactions between these constituents were either totally unknown or were the subject of severe misconceptions. The students’ knowledge tended to be qualitative and formal, with a worrying lack of connection with everyday life.     

Right or Wrong? Toward a Theory of IRBs’ (Dis)Approval of Research

No one would disagree that scientific research has been unethical—even criminal—at times. Institutional review boards (IRBs) play a fundamental role in protecting people from unethical criminological research. At the same time, IRBs, as social entities, are subject to a wide range of influences that may affect their decisions regarding the ethicality of research. This research note draws on the paradigm of pure sociology and the logic underpinning Black’s theory of law to propose a preliminary theory of IRBs’ (dis)approval of research. Specifically, it suggests that IRBs apply less social control to criminological research involving higher status researchers and lower status research participants and, therefore, those persons are more often involved in research. The paper concludes with theoretically situated, practical advice for how (1) IRBs can reduce their discrimination, and (2) criminological researchers can reduce IRBs’ disapproval of their projects and thereby increase their research output.     

Toward an understanding of academic self‐concept in distance education

Abstract

Academic self‐concept has been demonstrated to influence student success in distance education. The purpose of this study was to examine the nature of academic self‐concept in distance education and to determine its enhancers and detractors. It was determined that this construct is dynamic and multi‐faceted: the process of both learning as an adult and learning at a distance, as well as the content studied, influences academic self‐concept. Implications for both practice and further research are discussed.     

The time course of the syllable frequency effect in visual word recognition: evidence for both facilitatory and inhibitory effects in French

The present study tracked the time course of the syllable frequency effect in French visual word recognition, by varying the strength of spreading activation between letters and phonological syllables. The frequency of phonological first syllables and the frequency of orthographic first syllables were conjointly manipulated in two lexical decision tasks. In Experiment 1, word parsing into syllable units was supported by orthographic redundancy. No interaction between orthographic and phonological syllable frequency was found. In Experiment 2, word parsing into syllables was not marked by orthographic redundancy. Results showed an interaction between orthographic and phonological syllable frequency: the syllable frequency effect was inhibitory when orthographic syllable frequency was high, whereas it was facilitatory when orthographic syllable frequency was low. Decreasing the strength of syllable activation (i.e., with orthographic syllables of low frequency and ambiguous syllable boundaries) prevented the activation of lexical competitors before target word recognition, leading to a facilitatory effect of syllable frequency. The present study provides evidence that the net effect of syllable frequency is strongly related to its time course, and that the strength of syllable activation, which depends on orthographic properties, determines the direction of the net effect.     

30 min of treadmill walking at self-selected speed does not increase gait variability in independent elderly

Walking is one of the preferred exercises among elderly, but could a prolonged walking increase gait variability, a risk factor for a fall in the elderly? Here we determine whether 30 min of treadmill walking increases coefficient of variation of gait in elderly. Because gait responses to exercise depend on fitness level, we included 15 sedentary and 15 active elderly. Sedentary participants preferred a lower gait speed and made smaller steps than the actives. Step length coefficient of variation decreased ~16.9% by the end of the exercise in both the groups. Stride length coefficient of variation decreased ~9% after 10 minutes of walking, and sedentary elderly showed a slightly larger step width coefficient of variation (~2%) at 10 min than active elderly. Active elderly showed higher walk ratio (step length/cadence) than sedentary in all times of walking, but the times did not differ in both the groups. In conclusion, treadmill gait kinematics differ between sedentary and active elderly, but changes over time are similar in sedentary and active elderly. As a practical implication, 30 min of walking might be a good strategy of exercise for elderly, independently of the fitness level, because it did not increase variability in step and stride kinematics, which is considered a risk of fall in this population.