分类： 心理学 >> 认知心理学 分类： 心理学 >> 实验心理学 提交时间： 2021-02-25
摘要： 个体对刺激的反应不仅受刺激本身的影响，还会受到先前刺激的影响，表现为对当前试次中刺激的反应会受到前一试次的影响，即试次历史。本研究采用“线索-中性线索-靶子”范式探讨前一试次有效性对跨通道的非空间返回抑制的影响。实验1通过连续两个试次间的线索有效性考察在跨通道非空间返回抑制中试次历史的影响。为了在跨通道非空间返回抑制中减小试次历史的影响，实验2通过延长试次间时间间隔考察跨通道非空间返回抑制中试次历史的作用是否减小。结果发现，前一试次线索无效时，当前试次中的返回抑制效应量显著小于前一试次有效时，这种影响会根据试次中线索和靶子通道的不同而不同。并且当延长试次间的时间间隔可以有效地减少前一试次对当前试次的影响。因此本研究表明，试次历史能够对跨通道非空间返回抑制产生影响，并且这种影响可以通过增大试次间时间间隔来减小
分类： 心理学 >> 发展心理学 提交时间： 2021-02-25
摘要： The neural mechanism of orthographic-phonological integration was influenced by the temporal relationship of cross-modal stimuli. However, previous studies mainly investigated the neural mechanism of letter-speech sound integration in precise temporal synchrony or small temporal asynchrony conditions. In this study, character-speech sound integration was investigated in a relatively wide temporal window. Chinese characters were presented synchronously to the onset of speech sounds or before speech sound by 300 or 600 ms (referred as AV0, AV300 and AV600). ERP responses evoked by congruent condition (speech sounds were paired with congruent visual characters) and baseline condition (speech sounds were paired with Korean characters) were compared. Different electrophysiological markers were found in the temporal synchrony and temporal asynchrony conditions. In the AV0 condition, developing dyslexia (DD) and typically developing (TD) children showed similar congruency effect on P1, N170 and N300 components, demonstrating the influence of speech sound on visual character processing. In the AV300 condition, DD group showed left-lateralized congruency effect on N200, whereas TD children showed bilateral congruency effect on N200. Both groups showed bilateral congruency effect on N200 in the AV600 condition. We speculate that the insufficient character-speech sound integration exhibited by dyslexic children in the AV300 condition was probably caused by their slow visual processing speed. The results provide unique insight into the neural mechanism of print-speech integration in a wide temporal window and point out the necessity to investigate neural mechanism of print-speech integration in a relatively wide temporal window.
分类： 物理学 >> 核物理学 提交时间： 2021-02-25
摘要： In high energy resolution X-ray spectroscopy beamlines of synchrotron radiation (SR) facilities and laboratory XAS/XES spectrometer, it is important to keep X-ray spectrometer operating in optimal conditions. The adjusting process is normally very time consuming due to the irregular light source beam point, and it is difficult to get global optimum. This study aims to develop an intelligent adjusting system based on global optimization algorithm for spectrometers on SR beamlines and on laboratory x-ray source. First of all, based on the two dimensional experimental data, automatic adjustment process was established. Then the automatic optimization was applied to adjust X-ray spectrometer practically, and upgraded iteratively. The online testing is carried out on a self-developed laboratory XAS spectrometer. Online tests results show that this automatic adjustment process converges to the optimal solution quickly, and the convergence time is about several dozens to hundreds steps, more efficient than manual optimization process. After automatic adjustment, we can get correct X-ray absorption spectrum based on the adjusted spectrometer.
分类： 心理学 >> 心理学其他学科 提交时间： 2021-02-25
摘要： 目前关于运动员经验优势的脑机制还存在争议，尤其对于涉及较多认知过程参与的高策略性技能项目运动员，其大脑白质结构可塑性变化还需进一步探究。研究横向对比了乒乓球运动员和非运动员大脑白质纤维束的弥散张量成像数据。结果发现，相比于非运动员，乒乓球运动员在连接背侧和腹侧通路脑区的双侧皮质脊髓束、左侧上纵束、左侧下纵束和双侧额枕下束的各向异性值（FA）更大，进一步分析发现，部分腹侧通路白质纤维束FA增加的原因是径向扩散系数（RD）下降。研究结果支持了动作双通路模型。提示经过长期高策略性技能训练，乒乓球运动员在背侧和腹侧通路上的白质纤维束结构完整性增强。
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