A working memory account for spatial-numerical associations

Several psychophysical and neuropsychological investigations have suggested that the mental representation of numbers takes the form of a number line along which magnitude is positioned in ascending order according to our reading habits. A longstanding debate is whether this spatial frame is triggered automatically as intrinsic part of the number semantics or whether it constitutes a short-term representation constructed during task execution. Although several observations clearly favor the working memory account, its causal involvement has not yet been demonstrated. In two experiments we show that information stored in working memory get spatially coded in function of its ordinal position in the sequence and that the spatial–numerical associations typically observed in number categorization tasks draw upon this mechanism.     

数学学习困难初中生的中央执行系统特点

为揭示数学学习困难学生的认知过程加工特点,筛选上海111名初中生（男生46名,女生68名,平均年龄11.97岁）比较数学困难学生（55名）与数学优秀学生（56名）的中央执行系统的表现差异,通过反应停止任务和Flanker任务考察抑制能力以及注意控制能力。结果发现各种抑制和注意控制条件下,数困组学生的正确率低于数优组;在具有干扰的情况的成绩更能有效预测数学成绩;中央执行系统能力在初中总体具有上升发展趋势,数困生的发展具有波动性。因此,数学学习困难在中央执行系统中的缺损主要是对抗干扰的能力不足,而非简单的加工速度。     

内隐序列学习的表征机制及年龄效应研究

该研究从年龄效应这一独特视角探讨了内隐序列学习的表征机制。结果表明:(1)内隐序列学习存在具体联结和抽象层级编码双重表征机制,且在该研究中以抽象编码为主;(2)老、青、幼三组被试的内隐序列学习无显著差异,间接支持了具体联结机制不起主要作用的结论。该研究的推论是:(1)内隐序列学习的表征是一个遵循“最优级编码”的动态过程;(2)该过程不涉及注意机制和短时记忆。     

叙述文本中中心概念的确定方式及其通达

采用移动窗口技术考察叙述文本中中心概念的确定方式及其通达。实验一在中文条件下得出了与Michelle＆O’Brien2002研究一致的结果。实验二采用事件相关方式确定中心词．结果表明．无论在标题相关陪衬调还是在事件相关陪衬调干扰下。事件相关中心词通达效果显著优于边缘词。实验兰进一步比较事件相关中心概念与词频相关中心概念的通达效果。结果表明,前者通达效果显著优于后者。总的实验结果表明。事件相关中心的确定方式同样在叙述文本中具有适用性．能够很好地体现文本中心,表现出情境模型水平上的通达优势。     

工作记忆中央执行对儿童算术认知策略的影响

运用“双重任务”范式,以113名小学二年级儿童为被试,考察了儿童工作记忆的中央执行对算术认知策略表现的影响。结果表明:中央执行对儿童算术认知策略的选择产生了针对性的影响,集中表现在外部策略、支持性策略和猜测放弃策略上。中央执行干扰使策略执行的正确率下降、反应时增加。在简单加法任务上,中央执行影响了外部策略和支持性策略的选择频次;在复杂任务中,这种影响体现在外部策略和放弃策略上。无论是简单任务还是复杂任务,中央执行的干扰都造成了策略整体执行效果的下降。     

Are sensorimotor experiences the key for successful early intervention in infants with congenital brain lesion?

Living with a congenital brain lesion may have detrimental effects on the ability to do everyday activities, but contrary to acquired brain lesions, people and in particular children, with congenital brain lesions may have limited or no experience of how their bodies work. This absence of experience gives rise to challenges for habilitation of sensorimotor abilities and derived cognitive abilities. How can motor and cognitive abilities be achieved and trained in an individual with no experience of potential abilities? In this article, we aim to review the existing knowledge about the development of sensorimotor integration. Further, we will discuss this knowledge in the light of two neurocognitive theories: embodied cognition and predictive coding. Moreover, using developmental knowledge and theory in combination, we will argue that early sensorimotor development serves as a foundation for later cognitive development. Finally, we try to use these elements in a strategy to make interventions as early as possible, with the purpose of improving sensorimotor and cognitive abilities in children with congenital brain lesions.     

The effect of running speed on joint coupling coordination and its variability in recreational runners

The purpose of this study was to examine the effect of speed on coordination and its variability in running gait using vector coding analysis. Lower extremity kinematic data were collected for thirteen recreational runners while running at three different speeds in random order: preferred speed, 15% faster and 15% lower than preferred speed. A dynamical systems approach, using vector coding and circular statistics, were used to quantify coordination and its variability for selected hip-knee and knee-ankle joint couplings. The influence of running speed was calculated from the continuous data sets of the running cycle, allowing for the identification of time percentages where differences existed. Results indicate that increases in running speed produced moderate alterations in the frequency of movement patterns which were not enough to alter classification of coordination. No effects of speed on coordination variability were observed. This study has demonstrated that coordination and coordination variability is generally stable in the range of ±15% around of preferred speed in recreational runners.     

Movement segmentation and visual perturbation increase developmental differences in motor control and learning

We examined the developmental differences in motor control and learning of a two‐segment movement. One hundred and five participants (53 female) were divided into three age groups (7–8 years, 9–10 years and 19–27 years). They performed a two‐segment movement task in four conditions (full vision, fully disturbed vision, disturbed vision in the first movement segment and disturbed vision in the second movement segment). The results for movement accuracy and overall movement time show that children, especially younger children, are more susceptible to visual perturbations than adults. The adults’ movement time in one of the movement segments could be increased by disturbing the vision of the other movement segment. The children's movement time for the second movement segment increased when their vision of the first movement segment was disturbed. Disturbing the vision of the first movement segment decreased the percentage of central control of the second movement in younger children, but not in the other two age groups. The children's normalized jerk was more easily increased by visual perturbations. The children showed greater improvement after practice in the conditions of partial vision disturbance. As the participants’ age increased, practice tended to improve their feedforward motor control rather than their feedback motor control. These results suggest that children's central movement control improves with age and practice. We discuss the theoretical implications and practical significance of the differential effects of visual perturbation and movement segmentation upon motor control and learning from a developmental viewpoint.     

The influence of attention on holistic face encoding

We examined the influence of attention on the formation of holistic face representations using the composite effect (Perception 16 (1987) 747). In Experiment 1, stimuli composed of a face superimposed on a house were shown during encoding. Subjects delineated either the face or the house, thus manipulating attention away or toward the face. In Experiment 2, an intact face image was presented with letters scrolling from top to bottom. Subjects were asked to either ignore the letters or read them and decipher the words that they formed. Aligned and misaligned composites were shown at testing. Recognition performance was consistently better for misaligned than aligned stimuli, regardless of the allocation of attention during encoding. In Experiment 3, we show that the composite effect can be eliminated by a disruption in holistic processing at the time of encoding. We conclude that holistic encoding is one aspect of face analysis that occurs equally well with or without attention.     

Solving spatial tasks with unaligned layouts: the difficulty of dealing with conflicting information

Previous research has shown that preschool children have difficulty using relational information in spatial tasks. The present study investigates whether this difficulty is due, in part, to children's inability to deal with situations of conflict where both objective and egocentric cues are available and point to different responses. Two studies were conducted to compare performance in the presence versus absence of conflicting cues. In Study 1, 40 four-year-olds had to locate an object in a single layout presented from different perspectives. In Study 2, 39 four-year-olds had to transfer locational information between two unaligned layouts. The presence of conflict significantly affected children's performance in both studies. The results are discussed in the context of similar findings in other cognitive domains.