An integrative model of rational imitation in infancy

It has been proposed that infants selectively imitate based on a rational evaluation of an observed action (Gergely, Bekkering, & Király, 2002). This rational-imitation account has been rejected based on findings which suggested that infant imitation depends on: (a) the similarity between the infant's and the model's body posture; and (b) the presence of action effects (Paulus, Hunnius, Vissers, & Bekkering, 2011). Despite this controversy, we show that both accounts have received empirical support from different fields of research. We propose that both accounts operate on different levels, and we present an integrative model, which combines the two seemingly competing accounts. Motor resonance is perceived as a mechanism that enables infants to imitate, and a rational evaluation of the model's action is conceived as a mechanism that guides infants’ imitative behavior.     

Stability of deferred imitation in 12- to 18-month-old infants: A closer look into developmental dynamics

Deferred imitation is used to assess declarative memory in infants. Although a lot of studies show that infants from 6 months onwards are able to re-enact actions following a delay, only a few studies describe early declarative memory longitudinally. From a variable-centred approach, these studies found a modest relationship between measurement occasions that increases with age. However, no studies have analysed the differential aspect of memory development from a person-centred perspective. The present study analyses memory stabilities both from a variable-centred and person-centred approach within a sample of N = 87 infants of a 2-wave longitudinal design (12- and 18-month-olds). From a variable-centred perspective, the results indicate that, first, there was a significant increase in infants' memory performance and, second, that although reliable, the stability of infants' memory performance was relatively low. From a person-centred perspective two vs. three groups of infants were differentiated showing different developmental growth trajectories and stability correlations but no differences in language, cognitive and motor development. The implications of those results in terms of further test development are discussed. Furthermore, important methodological expansions for the analysis of infants' memory data are presented and discussed.     

Are Automatic Imitation and Spatial Compatibility Mediated by Different Processes?

Automatic imitation or “imitative compatibility” is thought to be mediated by the mirror neuron system and to be a laboratory model of the motor mimicry that occurs spontaneously in naturalistic social interaction. Imitative compatibility and spatial compatibility effects are known to depend on different stimulus dimensions—body movement topography and relative spatial position. However, it is not yet clear whether these two types of stimulus–response compatibility effect are mediated by the same or different cognitive processes. We present an interactive activation model of imitative and spatial compatibility, based on a dual‐route architecture, which substantiates the view they are mediated by processes of the same kind. The model, which is in many ways a standard application of the interactive activation approach, simulates all key results of a recent study by Catmur and Heyes (2011) . Specifically, it captures the difference in the relative size of imitative and spatial compatibility effects; the lack of interaction when the imperative and irrelevant stimuli are presented simultaneously; the relative speed of responses in a quintile analysis when the imperative and irrelevant stimuli are presented simultaneously; and the different time courses of the compatibility effects when the imperative and irrelevant stimuli are presented asynchronously.     

Social attitudes modulate automatic imitation

In naturalistic interpersonal settings, mimicry or “automatic imitation” generates liking, affiliation, cooperation and other positive social attitudes. The purpose of this study was to find out whether the relationship between social attitudes and mimicry is bidirectional: Do social attitudes have a direct and specific effect on mimicry? Participants were primed with pro-social, neutral or anti-social words in a scrambled sentence task. They were then tested for mimicry using a stimulus-response compatibility procedure. In this procedure, participants were required to perform a pre-specified movement (e.g. opening their hand) on presentation of a compatible (open) or incompatible (close) hand movement. Reaction time data were collected using electromyography (EMG) and the magnitude of the mimicry/automatic imitation effect was calculated by subtracting reaction times on compatible trials from those on incompatible trials. Pro-social priming produced a larger automatic imitation effect than anti-social priming, indicating that the relationship between mimicry and social attitudes is bidirectional, and that social attitudes have a direct and specific effect on the tendency to imitate behavior without intention or conscious awareness.     

α系数的区间估计方法比较

多数情况下,α系数可以用来评价测验信度。诸多研究建议,在报告测验信度的时候应当包括其置信区间。通过蒙特卡洛模拟研究,比较了7种α系数区间估计方法,包括Fisher法、Bonett-02法、Bonett-10法、精确Koning-Franses法、渐近ID法、渐近Koning-Franses法和ADF法。结果发现Bonett-10法和精确Koning-Franses法较好,它们的结果相差很小。这两种方法都比较简单,只需要样本的α值、测验题数、被试人数及F临界值,通过简单的运算便可得到α系数的置信区间。     

不同数学焦虑成人的算术策略运用差异：ERP研究

采用事件相关电位(ERP)技术和选择/无选法范式, 在两位数加法心算和估算中, 探索高、低数学焦虑个体的算术计算策略运用及其内在机制。行为结果：数学焦虑效应在策略运用的反应时和正确率指标上的差异都不显著; 而脑电结果：高数学焦虑个体的N400波幅显著高于低数学焦虑个体; 选择条件中, 估算与心算的数学焦虑效应的N100波幅差异; 无选条件中, 高低数学焦虑个体N1-P2复合波的波幅和潜伏期差异显著。数学焦虑效应在策略编码(0~250 ms)和策略选择/执行阶段(250 ms之后)存在差异。     

语言系统对不同数量系统的影响机制

已有研究较一致地发现语言加工系统对不同的数量加工系统起到不同作用, 表现为语言不影响概略数量和小数加工系统, 主要影响大数的精确加工系统。然而, 其影响机制并不明确。新近几年采用跟踪测验、语言转换、同语言内语音长度操控、双任务等范式来探索数量加工对语言依赖性的行为和脑机制研究。但结论不完全一致。通过记忆中介的视角可以为这些不一致提供新的解释。未来相关研究的思路应包括跟踪语言关键期幼儿的数量系统发展轨迹, 注意区分在记忆不同层面(长时/短时)中介下语言系统对数量系统的影响, 关注语义句法等对数量系统的作用, 以及深入了解基础四则运算的认知神经机制。     

How Working With a Helpful Versus Less Helpful Confederate Influences Joint-Action in a Pegboard Task

Actors change their movement strategies to complement a coactor's movements when performing cooperative tasks. To further investigate this topic, the authors designed a pegboard task whereby a participant-confederate pair worked together to move a peg from one side of the board to the other. The authors examined how the experience of working with a helpful confederate versus less helpful confederate influenced the participant's movement behavior. Results provide evidence that participants change their movement behaviors in response to the actions of the confederate. Here the human capacity to act in such a manner exemplifies an individual's ability to utilize his or her own action system to understand others and interact to complete joint action tasks. Individuals appear to adapt their behavior to their experiences, and thus may be helpful in some contexts and less helpful in others.