Dorsolateral prefrontal cortex mediates working memory processes in motor skill learning

Neuroimaging studies have shown that the dorsolateral prefrontal cortex (DLPFC) is recruited during motor skill learning, which suggests the involvement of the DLPFC in working memory (WM) processes, such as selection and integration of motor representations temporarily stored in WM. However, direct evidence linking activation of the DLPFC to WM storage and manipulation during motor skill learning in real-time is rare. In this study, we conducted two experiments to investigate the causal role of DLPFC activity in WM storage and manipulation during motor skill learning under low and high WM-demand conditions. Participants received continuous theta burst stimulation (cTBS) and sham stimulation (crossover design) over the left DLPFC (experiment 1) or right DLPFC (experiment 2). Before and after stimulation, participants in both experiments performed a sequential finger-tapping (SFT) task containing repeated sequence (low-WM demand) and non-repeated sequence (high-WM demand) conditions which are used to study WM processes. The number of correct sequences (NoCS) and reproduction error rate were analyzed. Learning gains in NoCS improved significantly with the practice for both sequence types in the presence of either stimulation type. Compared to sham stimulation, cTBS over the left DLPFC resulted in significantly reduced learning gains in NoCS for non-repeated sequences. These results suggest that the left DLPFC contributes to WM manipulation during motor skill learning.     

来自屏幕的纽带：视频聊天与儿童发展

随着近几年视频聊天的兴起, 越来越多的研究者开始探索视频聊天对儿童发展的影响。相较于传统通讯技术, 视频聊天具备了视听结合与即时互动的特征; 但同时, 作为数字媒体, 视频聊天仍然保持了传统屏幕媒体二维性的特征。汇总以往视频聊天与儿童学习的实证研究发现, 与录制视频教学比较, 视频聊天在婴幼儿词汇学习(d = 0.33)和动作学习(d = 0.90)上的教学效果更佳; 同时, 视频聊天也能够使婴幼儿在教学过程中保持较高的注意水平(d = 0.90)。视频聊天对儿童远距离亲子关系和同伴关系上均有一定的促进作用。视频聊天也可以作为一种辅助治疗手段应用于特殊儿童的干预中。未来研究仍需关注扩大视频聊天学习中儿童被试的年龄范围、共同观看者的不同支持行为对儿童视频聊天学习的效果产生的影响。     

阅读方式和学习次数对中文词汇的产生效应影响的发展研究

产生效应指朗读单词的记忆成绩要好于默读单词的记忆成绩。采用“学习-再认”的实验范式,以小学三年级、小学五年级、初一、初二和大学生为被试,采用2（阅读方式：朗读,默读）×2（学习次数：1次,3次）×5（年级：三年级,五年级,初一,初二,大学）的混合设计,探讨中文词汇产生效应的发展特点。结果发现：（1）年级的主效应显著,大学生的记忆成绩显著高于三年级、五年级和初一学生的;五年级、初一和初二学生的记忆成绩显著高于三年级学生的;（2）阅读方式的主效应显著,朗读的记忆成绩显著高于默读的;（3）学习次数的主效应显著,3次的记忆成绩显著高于1次的;（4）阅读方式和年级的交互作用显著,在朗读的记忆成绩上,小学三年级的与大学生的差异显著,但小学五年级、初一、初二学生的和大学生的差异均不显著,说明朗读的记忆成绩在小学五年级趋于成熟;在默读的记忆成绩上,小学三年级、五年级、初一学生的均与大学生的差异显著,初二学生的与大学生的无显著差异,表明默读的记忆成绩在初二年级趋于成熟。初一学生的产生效应大小与大学生的无差异。研究结果支持产生效应的特异观。     

无聊倾向对青少年网络成瘾的影响：一个有调节的中介模型

为探究无聊倾向对青少年网络成瘾的预测作用和影响机制,选取云南省和山东省5所普通中学的1553名青少年进行调查。结果发现：（1）青少年无聊倾向显著正向预测网络成瘾;（2）学习倦怠在青少年无聊倾向与网络成瘾之间起中介作用;（3）积极应对方式在无聊倾向与学习倦怠之间起调节作用。本研究结果揭示了青少年网络成瘾形成的内部机制,并基于I-PACE模型构建了青少年网络成瘾的形成过程模型,为青少年网络成瘾的干预提供决策依据。     

网络教学情境下正念对学业拖延的影响：心理韧性和自我控制的链式中介作用

本研究以157名大学生为对象,选用正念五因素量表、心理韧性量表、自我控制量表和Aitken拖延量表,探索在网络教学情境下正念对学业拖延的作用机制。结果表明：正念能够直接对网络教学情境下的大学生学业拖延产生影响,也能够通过心理韧性和自我控制的链式中介作用对大学生学业拖延产生影响。研究结论为发挥正念的作用,改善网络教学情境下的学业拖延提供了参考。     

Distributional learning has immediate and long-lasting effects

Evidence of distributional learning, a statistical learning mechanism centered on relative frequency of exposure to different tokens, has mainly come from short-term learning and therefore does not ostensibly address the development of important learning processes. The present longitudinal study examines both short- and long-term effects of distributional learning of phonetic categories on non-native sound discrimination over a 12-month period. Two groups of listeners were exposed to a two-minute distribution of auditory stimuli in which the most frequently presented tokens either approximated or exaggerated the natural production of the speech sounds, whereas a control group listened to a piece of classical music for the same length of time. Discrimination by listeners in the two distribution groups improved immediately after the short exposure, replicating previous results. Crucially, this improvement was maintained after six and 12 months, demonstrating that distributional learning has long-lasting effects.     

Conscious awareness of action potentiates sensorimotor learning

Many everyday skills are unconsciously learned through repetitions of the same behaviour by binding independent motor acts into unified sets of actions. However, our ability to be consciously aware of producing newly and highly trained motor skills raises the question of the role played by conscious awareness of action upon skill acquisition. In this study we strengthened conscious awareness of self-produced sequential finger movements by way of asking participants to judge their performance in terms of maximal fluency after each trial. Control conditions in which participants did not make any judgment or performance-unrelated judgments were also included. Findings indicate that conscious awareness of action, enhanced via subjective appraisal of motor efficiency, potentiates sensorimotor learning and skilful motor production in optimising the processing and sequencing of action units, as compared to the control groups. The current work lends support to the claim that the learning and skilful expression of sensorimotor behaviours might be grounded upon our ability to be consciously aware of our own motor capability and efficiency.     

A hierarchy of cortical responses to sequence violations in three-month-old infants

The adult human brain quickly adapts to regular temporal sequences, and emits a sequence of novelty responses when these regularities are violated. These novelty responses have been interpreted as error signals that reflect the difference between the incoming signal and predictions generated at multiple cortical levels. Do infants already possess such a hierarchy of violation-detection mechanisms? Using high-density recordings of event-related potentials during an auditory local–global violation paradigm, we show that three-month-old infants process novelty in temporal sequences at two distinct levels. Violations of local expectancies, such as perceiving a deviant vowel “a” after repeated presentation of another vowel i-i-i, elicited an early auditory mismatch response. Conversely, violations of global expectancies, such as hearing the rare sequence a-a-a-a instead of the frequent sequence a-a-a-i, modulated this early mismatch response and led to a late frontal negative slow wave, whose cortical sources included the left inferior frontal region. These results suggest that the infant brain already possesses two dissociable systems for temporal sequence learning.     

Revisiting Chinese‐speaking children's understanding of argument structure

A causative verb is likely to appear in a sentence with two noun arguments, whereas a noncausative verb tends to appear in a sentence with a single argument. The present research investigates from what point children learning Chinese begin to show this knowledge of argument structure. Two‐, 3‐, 4‐, and 5‐year‐old children were tested using a forced‐choice pointing task. The results showed that Chinese‐speaking children aged 2 years could associate a transitive construction with a causative event, whereas they were not able to map an intransitive construction to a noncausative event even after reaching 5 years of age. The reason why Chinese children have such difficulty in learning knowledge of intransitive construction is discussed, focusing on (a) the semantic properties of certain intransitive verbs, which have been found not only in Chinese but also in other languages, and (b) the ellipsis of arguments, which is characteristic of Chinese.