The cues that infants use to distinguish discontinuous quantities: evidence using a shift-rate recovery paradigm

A novel experimental method, shift-rate recovery, was developed and used in a series of three experiments. These examined the extent to which 6-month-old infants (N = 131) find perceptual cues such as density and length useful in the discrimination of linearly arranged sets containing large numbers of objects. Results showed that infants discriminated between arrays that differ in number and density, with length held constant, when the arrays were presented either simultaneously or successively. On the other hand, infants discriminated only between arrays that differ in number and length, with density held constant, when the arrays were presented simultaneously. Infants were, however, able to perform a successive length discrimination when the arrays were continuous rather than consisting of discrete items. These findings support the conclusion that infants are able to discriminate between large number sets by relying on absolute cues such as density (but not length) and on relative cues such as optical one-to-one correspondence.     

Learners＇ and teachers＇ conceptions and dispositions of mathematics from a Middle Eastern perspective

The paper discusses an on-going research project that studies students＇ and teachers＇ conceptions and dispositions of mathematics. Conceptions are the views that students hold on a subject, and what they believe is required in learning and doing the subject. Dispositions are the beliefs or tendencies to exhibit a frequent, conscious and voluntary behavior directed towards learning a subject. The participants are high school students, higher education students and mathematics teachers. The study utilizes self-reporting tools as well as focus groups and interviews in a three-stage research model. This is a work on progress. Results to date are briefly discussed.     

Physiological Responses to Maximal Treadmill and Handweighted Exercise

Abstract

The purpose of this investigation was to compare the peak physiological responses among four protocols that employed different amounts of handweighted exercise in 16 males (aged 26.3 ± 4.1 years). The four protocols were (a) uphill treadmill running (UR; 3.36 m-s¹, 2.5% grade increase-3 min¹); (b) uphill treadmill walking while pumping 1.36kg handweights (HW) (UWHW; 1.79ms¹, 5.0% grade increase-3 min¹; (c) treadmill walking while pumping .91-kg HW (WHW; 1.79 m-s¹, 0% grade, .91kg HW increase-3 min¹); and (d) standing in place and pumping HW (SHW; arm work as described in WHW). It was hypothesized that the peak responses would be inversely proportional to the estimated muscle mass activated (i.e., UR = UWHW > WHW > SHW). Dependent variables included peak oxygen uptake (VO₂ peak), peak heart rate (HRpeak), peak ventilation (V_epeak), and peak respiratory exchange ratio (RERpeak). No differences were noted between UR and UWHW with respect to any of the dependent variables. All variables (except RERpeak) were greater (p < .01) in UR and UWHW than either WHW or SHW. RERpeak was greater (p < .01) in UR and UWHW than in WHW. VO₂peak and HRpeak were greater (p < .01) in WHW when compared to SHW. Mean VO₂peak was 97.5, 69.7, and 60% of UR for UWHW, WHW, and SHW, respectively. Therefore, walking and pumping handweights provides a maximal stimulus to the oxygen transport system.     

Lower limb muscle strength and physical activity in healthy individuals approaching retirement

Abstract

The purpose of this study was to examine knee extensor/flexor muscle strength and physical activity in healthy males and females approaching retirement. Peak torques of the knee extensor and knee flexor muscle groups were measured bilaterally in 95 individuals (mean age 59.4 years) using an isokinetic dynamometer. Isokinetic concentric contractions were performed at angular velocities of 1.05 and 3.14 rad · s^?1. Physical activity, including household, leisure, and sporting activities, was assessed. The results show that the average peak torques exhibited were lower than previously reported in studies using the same methodology with different populations of similar age and body size. Over one-third of the participants were sedentary, with just 13% being active enough to obtain health benefits. The poor muscle strength and low physical activity of this self selecting group of healthy working adults were surprising, and potentially a cause for concern. The combination of retirement being a potential watershed for a decrease in physical activity and the known age-related decline in physical performance indicates that some of these participants are at risk of losing their functional independence fairly early in the retirement stage. We recommend the introduction of effective health promotion interventions for individuals approaching retirement, encouraging them to become more physically active.     

Theoretical and methodological pitfalls in making comparisons between developmental and acquired dyslexia: Some comments on A. Castles & M. Coltheart (1993)

On the basis of a study of the reading skills of 56 developmental dyslexics, Castles & Coltheart (1993) have proposed that there are at least two varieties of dyslexia in children. In the first, there is an impairment of lexical reading and in the second, the operation of the sublexical procedure is impaired. We take issue with their, proposal on theoretical grounds and argue that methodologlcal weaknesses in their study seriously weaken their claims.     

First-grade cognitive abilities as long-term predictors of reading comprehension and disability status

In a sample of 195 first graders selected for poor reading performance, the authors explored four cognitive predictors of later reading comprehension and reading disability (RD) status. In fall of first grade, the authors measured the children's phonological processing, rapid automatized naming (RAN), oral language comprehension, and nonverbal reasoning. Throughout first grade, they also modeled the students' reading progress by means of weekly Word Identification Fluency (WIF) tests to derive December and May intercepts. The authors assessed their reading comprehension in the spring of Grades 1-5. With the four cognitive variables and the WIF December intercept as predictors, 50.3% of the variance in fifth-grade reading comprehension was explained: 52.1% of this 50.3% was unique to the cognitive variables, 13.1% to the WIF December intercept, and 34.8% was shared. All five predictors were statistically significant. The same four cognitive variables with the May (rather than December) WIF intercept produced a model that explained 62.1% of the variance. Of this amount, the cognitive variables and May WIF intercept accounted for 34.5% and 27.7%, respectively; they shared 37.8%. All predictors in this model were statistically significant except RAN. Logistic regression analyses indicated that the accuracy with which the cognitive variables predicted end-of-fifth-grade RD status was 73.9%. The May WIF intercept contributed reliably to this prediction; the December WIF intercept did not. Results are discussed in terms of a role for cognitive abilities in identifying, classifying, and instructing students with severe reading problems.     

The power of student resistance in action research: teacher educators respond to classroom challenges

The purpose of this research was to study the design and implementation of a newly developed, two‐semester, action research course in a Master of Arts in Teaching program. Over a four‐year period, we (the instructors) used action research methodologies for analysis and evaluation of the course. Throughout this study, students expressed varying reactions to the process of action research, ranging from enthusiasm and acceptance to continual and persistent reluctance to accept the process as ‘real research’. This resistance is the focus of our study. Four years of reflection on our data points to the following reasons for student resistance: lack of understanding about what action research is and its purpose; a discomfort with the emphasis of process over product and the associated investment of time and ability to multi‐task; and willingness to embrace the transformational process of action research as part of learning to teach.     

The appeal of rough‐and‐tumble play in televised professional football

In a factorial design varying (1) the degree of roughness/violence of a play (low, intermediate, and high), (2) several particular plays within this classification, and (3) sex of viewer, the enjoyment of televised plays of professional football was investigated. The plays were taken from a large pool of plays drawn from numerous games and involving numerous teams. In a pretest, a strong differentiation in the selection plays' degree of roughness/violence was secured. At the same time, the plays were matched on several other, potentially contaminating stimulus dimensions. The enjoyment of plays was found to increase with the degree of their apparent roughness/violence. However, this relationship was significant for male viewers only. It was not reliable for females. There were no appreciable sex differences in the enjoyment of plays featuring low and intermediate levels of roughness. Highly violent plays, in contrast, were significantly more enjoyed by males than by females. The findings suggest that, at least for male viewers, a high degree of aggressiveness is a critical ingredient of the enjoyment of watching sports contests.     

Emerging Adult Siblings' Use of Verbally Aggressive Messages as Hurtful Messages

The purpose of this study was to identify the specific types of verbally aggressive messages emerging adult siblings use with each other and to determine whether these types of verbally aggressive messages differ in perceived hurtfulness, intensity, and intent. Participants were 115 individuals who identified a verbally aggressive message recently used by a sibling. Results indicated that siblings use seven types of verbally aggressive messages (i.e., name calling, insults, withdrawal, physical acts or threats, repudiating the relationship, negative affect, unfair comparison), and the seven types of verbally aggressive messages do not differ in their perceived hurtfulness, intensity, and intent.