What cognitive and numerical skills best define learning disabilities in mathematics? / ¿Qué habilidades cognitivas y numéricas definen mejor las dificultades de aprendizaje en matemáticas?

Differentiating students with mathematical learning disabilities (MLD) from those with low achievement (LA) is still an unresolved issue. This study explored whether the specific combination of certain cognitive and numerical skills can classify students with MLD, with LA, and without MLD. In order to do this, an analysis was carried out of the performance of 756 Spanish students in grades two to six, on different numerical and cognitive tasks. Two factors were extracted using a principal component analysis of the tasks: a semantic-cognitive factor and a verbal-automation factor. The results obtained from comparing the groups showed that students with MLD and LA demonstrated significant differences in the semantic-cognitive factor, and that these differences were consistent across grade levels. In contrast, there were no differences between groups in the automatic-verbal factor. These results confirm that the groups are not only quantitatively different but also qualitatively different.     

关于我国学生汉语阅读困难的研究

旨在探讨在我国学生的汉语学习中是否存在阅读困难问题。研究分别采用了目前国外较常使用的两种阅读困难操作定义和新近提出的截点法,对我国学生汉语学习中的阅读困难问题进行了考查。结果揭示出阅读困难在汉语学习者中同样存在,检出率分别为４．５５％和７．９６％．中国学生的阅读困难既表现在词汇上也表现在理解上;研究还发现同为阅读困难者男生和女生呈现出不同的特点。     

Failed back surgeries and minnesota multiphasic personality inventory (MMPI) profiles

MMPI profiles were evaluated for 105 prospective surgical patients who had previously undergone surgery or other procedures for treatment of back pain. Patients were classified into groups having undergone zero, one, two, three, or four or more previous surgeries. While all groups demonstrated a characteristicsomatogenic profile, none of the MMPI validity or clinical scales significantly differentiated the groups and there was no relationship between increased number of surgeries and MMPI scale characteristics. These results support the nonoptimistic prognostication of thesomatogenic MMPI profile for surgical intervention for back pain but show no clear relationship of MMPI profile characteristics to degree of experience of previously failed surgery.     

Concurrent activities and instructed human fixed-interval performance.

Two experiments explored the effects of two types of concurrent activity on human fixed-interval performance. Eight adult subjects were given access to either reading material or a working television set across three fixed-interval values (60 s, 300 s, and 600 s). During Experiment 1, 2 subjects produced "scalloped" patterns and reported no verbal regulation (e.g., counting) in the presence of the reading material, but shifted to low-rate patterns and reported verbal regulation when the reading material was withdrawn. The 2 other subjects in Experiment 1 produced consistent low-rate performances and reported verbal regulation during access to reading material. However, when these subjects were given access to a working television set, they produced scalloped patterns and reported no verbal regulation. During Experiment 2, 4 experimentally naive subjects showed consistent scalloped patterning and no verbal regulation across fixed-interval values when they were allowed to watch television. When access to the television was denied, subjects reliably reported verbal regulation, and low-rate patterns emerged. These behavioral effects focus our attention on the contingencies that control human performance on fixed-interval schedules.     

Species differences in temporal control of behavior II: human performance

Human subjects responded on two panels. A differential-reinforcement-of-low-rate schedule with a limited-hold contingency operated on Panel A. In Condition 1, responses on Panel B produced a stimulus on the panel that signalled whether reinforcement was available on Panel A. In Condition 2, responses on Panel B briefly illuminated a digital clock. In both conditions, performance on Panel A was very efficient; with few exceptions, Panel A was pressed only when reinforcement was available. Thus, in effect, a fixed-interval schedule operated on Panel B. In Condition 1, a “break-and-run” response pattern occurred on Panel B; with increasing temporal parameters, the duration of the postreinforcement pause on Panel B increased linearly while overall response rate and running rate (calculated by excluding the postreinforcement pauses) remained approximately constant. In Condition 2, the response pattern on Panel B was scalloped; the postreinforcement pause was a negatively accelerated increasing function of schedule value, while overall response rate and running rate were negatively accelerated decreasing functions of schedule value. The performance of subjects in Condition 2, but not in Condition 1, was highly sensitive to the contingencies in operation, and resembled that of other species on the fixed-interval schedule.     

Reduced visual acuity is mirrored in low vision imagery

Research has examined the nature of visual imagery in normally sighted and blind subjects, but not in those with low vision. Findings with normally sighted subjects suggest that imagery involves primary visual areas of the brain. Since the plasticity of visual cortex appears to be limited in adulthood, we might expect imagery of those with adult-onset low vision to be relatively unaffected by these losses. But if visual imagery is based on recent and current experience, we would expect images of those with low vision to share some properties of impaired visual perception. We examined key parameters of mental images reported by normally sighted subjects, compared to those with early- and late-onset low vision, and with a group of subjects with restricted visual fields using an imagery questionnaire. We found evidence that those with reduced visual acuity report the imagery distances of objects to be closer than those with normal acuity and also depict objects in imagery with lower resolution than those with normal visual acuity. We also found that all low vision groups, like the normally sighted, image objects at a substantially greater distance than when asked to place them at a distance that ‘just fits’ their imagery field (overflow distance). All low vision groups, like the normally sighted, showed evidence of a limited visual field for imagery, but our group with restricted visual fields did not differ from the other groups in this respect. We conclude that imagery of those with low vision is similar to that of those with normal vision in being dependent on the size of objects or features being imaged, but that it also reflects their reduced visual acuity. We found no evidence for a dependence on imagery of age of onset or number of years of vision impairment.     

儿童认知发展水平诊断工具IPDT的动态化编制及其在低社会经济地位儿童中的应用

“皮亚杰认知发展量表” (IPDT)中的守恒与关系领域经动态化改编后已被证实适用于小学低年级儿童的潜能评估。在此基础上, 本研究旨在构建适用于小学高年级儿童的IPDT表征、分类、规律领域的动态测验; 并运用所构建的IPDT动态测验对低社会经济地位(SES)儿童进行认知潜能评估; 而后经过对低SES儿童的推理认知干预, 进一步考查认知干预在低SES不同潜能儿童的认知能力和数学成就中的促进作用。结果发现：(1)改编的IPDT表征、分类、规律领域的动态测验包含“前测—干预—迁移—后测”4个阶段, 所构建的逐级提示干预方案合理适切, 可以有效区分不同认知潜能水平的小学高年级儿童, 特别是弱势儿童; (2)推理认知干预对由IPDT动态测验细致区分出的不同潜能水平的低SES儿童作用不同, 尽管他们在认知能力与数学成就上均有进步, 但低SES高潜能儿童比低SES低潜能儿童从干预中获益更多。     

目标显著性和任务重要性对数学学业不良生和学优生前瞻记忆和前瞻干扰效应的影响

有问卷调查表明,个体的学业成绩特别是数学成绩与前瞻记忆表现有一定的相关,学业不良生报告更多的前瞻记忆失败。也有实验研究显示,学业不良生在很多情况下前瞻记忆表现劣于学优生。但是,影响学业不良生前瞻记忆表现的因素却并不是很明确。本研究从目标显著性和任务重要性这两个可以着手于改善前瞻记忆的主要因素入手,考察其对数学学业不良生和学优生事件性前瞻记忆和前瞻干扰效应的影响,以期为提高学业不良生的前瞻记忆表现提供实证依据。 采用2学业成就（学业不良生、学优生）×2前瞻记忆任务重要性（强调重要、不强调）×2目标显著性（显著、不显著）混合实验设计,目标显著性为被试内变量,其他两个因素为被试间变量,在双任务实验范式（前瞻记忆任务镶嵌于进行中任务）中,考察三个因素对前瞻记忆正确率和反应时的影响。此外,被试还需完成基线条件,在基线条件下被试只有进行中任务,没有前瞻记忆任务,通过实验条件和基线条件的正确率和反应时差异,考察前瞻记忆任务对进行中任务的干扰效应,推测前瞻记忆的加工机制。结果表明,学业不良生在所有前瞻记忆任务表现均劣于学优生;目标显著性与前瞻记忆任务重要性对前瞻记忆正确率有显著的交互作用,强调任务重要性使目标不显著条件下的前瞻记忆正确率提高,对显著条件的前瞻记忆正确率没有影响。强调任务重要性使所有实验条件的前瞻记忆反应时下降,目标显著使所有实验条件的前瞻记忆正确率提高。所有实验条件进行中任务正确率低于基线条件,反应时也慢于基线条件,表明执行前瞻记忆任务对进行中任务产生了干扰,学业不良生和学优生在本实验条件下对前瞻记忆任务均采用监控的加工方式。结果说明,学业不良生前瞻记忆成绩较差,可以通过设置显著的目标提高其前瞻记忆成绩,当目标显著时无需强调其重要性,若无法设置显著的目标,则通过强调任务重要性提高前瞻记忆表现。     

ROLE OF FIRST‐YEAR MATERNAL EMPLOYMENT AND PATERNAL INVOLVEMENT IN BEHAVIORAL AND COGNITIVE DEVELOPMENT OF YOUNG CHILDREN

Drawing on economic models of child development and attachment relationship perspectives, this study examined the effect of maternal employment in the first year after childbirth on subsequent behavioral and cognitive development in low‐income children. Analyses of data from the Project on Human Development in Chicago Neighborhoods (N = 411) revealed that despite the accompanying family income gains, maternal employment in the first year after childbirth adversely affected caregiver‐reported internalizing and externalizing behavior problems of Hispanic, Black, and White children at ages 3 and 5 years. This study also examined how paternal participation in childcare might affect children's outcomes. Results indicate that greater paternal participation eased the adverse impacts of maternal employment on internalizing behavior problems. There was no evidence that maternal employment was associated with children's memory cognitive functioning or that paternal involvement moderated children's cognitive development. These findings suggest that when early intervention programs are designed to assist low‐income families, enhancing supports (e.g., paternal involvement or parental leave) for working mothers during their child's first year may be valuable for young children's healthy development.     

Assessment and treatment of low-rate high-intensity problem behavior.

Functional analysis of low‐rate aggression was conducted during extended observation periods and showed behavior to be maintained by positive reinforcement. Treatment consisted of variable‐momentary differential reinforcement of other behavior and was successful in reducing problem behavior throughout these extended observation periods.