Visual working memory load disrupts the space‐based attentional guidance of target selection

During visual search, the selection of target objects is guided by stored representations of target‐defining features (attentional templates). It is commonly believed that such templates are maintained in visual working memory (WM), but empirical evidence for this assumption remains inconclusive. Here, we tested whether retaining non‐spatial object features (shapes) in WM interferes with attentional target selection processes in a concurrent search task that required spatial templates for target locations. Participants memorized one shape (low WM load) or four shapes (high WM load) in a sample display during a retention period. On some trials, they matched them to a subsequent memory test display. On other trials, a search display including two lateral bars in the upper or lower visual field was presented instead, and participants reported the orientation of target bars that were defined by their location (e.g., upper left or lower right). To assess the efficiency of attentional control under low and high WM load, EEG was recorded and the N2pc was measured as a marker of attentional target selection. Target N2pc components were strongly delayed when concurrent WM load was high, indicating that holding multiple object shapes in WM competes with the simultaneous retention of spatial attentional templates for target locations. These observations provide new electrophysiological evidence that such templates are maintained in WM, and also challenge suggestions that spatial and non‐spatial contents are represented in separate independent visual WM stores.     

Changes of lumbosacral joint compression force profile when walking caused by backpack loads

Walking with backpack loads induces additional mechanical stress on the spine and has been identified as a risk factor of lower-back pain. This study evaluated the effects of walking with backpack loads on the lumbosacral joint compression force profile in both the magnitude and time domains. Ten male adults geared with anatomical markers and trunk surface electromyographic sensors walked along a walkway embedded with three force plates with no load and various backpack loads (5%, 10%, 15%, and 20% body weight). Lower-body movements, ground reaction forces, and trunk muscle activations were measured using a synchronized motion analysis, force plate, and surface electromyography system. The force profiles of identified gait cycles were predicted using an integrated inverse dynamic and electromyography-assisted optimization model and evaluated statistically. The results showed that as backpack load increased, the 10th, 50th, and 90th percentiles of force profiles escalated disproportionately. However, no significant changes were observed in the timing of the two peak force incidences. Such changes in the compression force might be an indication of the combined effects of the increase in both gravitational and mass moment of inertia of the system (body plus pack loads) when walking with a backpack. Pearson correlation coefficients of the force profiles between the five loading conditions were greater than 0.94. Strong associations between the force profiles at different backpack loads were confirmed.     

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.     

工作记忆负荷和自动化提取对小学生加法心算策略执行效果的影响

本研究选取43名小学四年级学生(18名男生和25名女生)为实验被试,探究了工作记忆负荷和自动化提取对复杂加法心算策略效果的影响.结果显示:(1)工作记忆负荷对复杂加法心算策略的影响显著,即一项加法心算策略所需的工作记忆负荷越小,该策略的执行效果越好;(2)自动化提取对加法心算策略的影响显著,即一项加法心算策略所需自动化提取的程度越高,该策略的执行效果越好;(3)工作记忆负荷和自动化提取对加法心算策略效果的交互作用显著,表现为在自动化提取水平较高的情况下,工作记忆负荷的大小对心算策略执行效果的影响差异不显著;而在自动化提取水平较低的情况下,工作记忆负荷小的心算策略的执行效果显著优于工作记忆负荷大的心算策略的执行效果.     

自我姓名加工的相对独特性：来自RSVP的证据

研究采用注意瞬脱的双任务RSVP范式通过操纵T1任务知觉负载水平的高低及T1-T2间的延迟长短,检验不同负载和延迟条件被试对陌生姓名、明星姓名和自我姓名的识别正确率。研究发现,自我姓名加工具有明显的注意瞬脱对抗效应,体现出加工的独特性,但其独特性受负载及延迟条件的影响,且明星姓名在一定条件下也出现了与之相近注意瞬脱的对抗效应,证明自我姓名加工具有相对的独特性。     

英语多媒体学习中言语关联手势对认知负荷的影响

为了探讨英语多媒体学习中言语关联手势对认知负荷及学习成绩的影响,采用2×2被试间实验设计。结果发现：该手势对认知负荷影响的主效应不显著,但与英语语言技能水平之间存在交互作用,当学生语言技能水平低时,手势增加了认知负荷,反之,则降低认知负荷;该手势对句子转换的成绩没有明显影响,但在学生语言技能高时能提升理解能力的成绩。本研究结果提示,言语关联手势的运用有明显作用,它能提高或降低认知负荷,并对理解能力的成绩产生影响,但其大小和方向依赖于学生英语语言技能水平。     

The role of cognitive control mechanisms in selective attention towards emotional stimuli

The role of cognitive control mechanisms in reducing interference from emotionally salient distractors was investigated. In two experiments, participants performed a flanker task in which target-distractor affective compatibility and cognitive load were manipulated. Differently from past studies, targets and distractors were presented at separate spatial locations and cognitive load was not domain-specific. In Experiment 1, words (positive vs. negative) and faces (angry, happy or neutral faces), were used respectively as targets and distractors, whereas in Experiment 2, both targets (happy vs. angry) and distractors were faces. Findings showed interference from distractor processing only when cognitive load was high. The present findings indicate that, when targets and distractors are presented at different spatial locations, cognitive control mechanisms are involved in preventing interference from positive (Exp. 1) or negative distractors (Exp. 2). The role of stimulus valence and type is also discussed with regard to different patterns of interference observed.     

知觉负载对负性分心面孔的知觉加工和记忆的影响

本研究采用视觉搜索和意外再认记忆任务,结合事件相关电位技术,考察知觉负载对负性分心面孔的知觉加工和记忆的影响。在视觉搜索任务中,行为上恐惧分心面孔在高负载下干扰任务。ERP结果上,恐惧比中性分心面孔诱发更大的N170和N250;在低负载下恐惧比中性分心面孔诱发更大的N700,在高负载下没有差异。在意外再认记忆中,个体对低负载下的恐惧分心面孔表现出记忆。这些结果说明负性分心物在早期是自动化加工;晚期加工受知觉负载的调节,负载越低对负性分心物的过滤越少,存在对负性分心物的记忆偏向。     

Cognitive load selectively interferes with utilitarian moral judgment

Traditional theories of moral development emphasize the role of controlled cognition in mature moral judgment, while a more recent trend emphasizes intuitive and emotional processes. Here we test a dual-process theory synthesizing these perspectives. More specifically, our theory associates utilitarian moral judgment (approving of harmful actions that maximize good consequences) with controlled cognitive processes and associates non-utilitarian moral judgment with automatic emotional responses. Consistent with this theory, we find that a cognitive load manipulation selectively interferes with utilitarian judgment. This interference effect provides direct evidence for the influence of controlled cognitive processes in moral judgment, and utilitarian moral judgment more specifically.     

Coding strategies in number space: memory requirements influence spatial-numerical associations

The tendency to respond faster with the left hand to relatively small numbers and faster with the right hand to relatively large numbers (spatial numerical association of response codes, SNARC effect) has been interpreted as an automatic association of spatial and numerical information. We investigated in two experiments the impact of task-irrelevant memory representations on this effect. Participants memorized three Arabic digits describing a left-to-right ascending number sequence (e.g., 3-4-5), a descending sequence (e.g., 5-4-3), or a disordered sequence (e.g., 5-3-4) and indicated afterwards the parity status of a centrally presented digit (i.e., 1, 2, 8, or 9) with a left/right keypress response. As indicated by the reaction times, the SNARC effect in the parity task was mediated by the coding requirements of the memory tasks. That is, a SNARC effect was only present after memorizing ascending or disordered number sequences but disappeared after processing descending sequences. Interestingly, the effects of the second task were only present if all sequences within one experimental block had the same type of order. Taken together, our findings are inconsistent with the idea that spatial-numerical associations are the result of an automatic and obligatory cognitive process but do suggest that coding strategies might be responsible for the cognitive link between numbers and space.