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131.
132.
The proportion of time allocated to one component of a concurrent variable-interval variable-interval schedule was computed for groups of interchangeover times (aggregates) within several intact time series. Variability in obtained proportions decreased as the number of interchangeover times within each aggregate increased; however, modal proportions failed to correspond to overall relative time allocation computed over the course of an entire experimental session, even at the largest aggregate size. The aggregated time series showed periodicities at small aggregate sizes and general trends in local preference at larger aggregate sizes. It is suggested that overall relative time allocation represents a molar extreme in the aggregation of behavior that may not accurately reflect central tendency in the allocation of time to available alternatives within the context of ongoing behavior.  相似文献   
133.
本研究以老年抑郁量表、自评抑郁量表和汉密顿抑郁量表为工具筛选出老年抑郁个体和老年正常对照组为研究对象,通过空间线索化范式,以及分离的情绪Stroop范式考察了刺激呈现时间、线索呈现条件对老年抑郁个体注意偏向的影响,并探讨了老年抑郁个体注意偏向的发生阶段。研究结果表明:(1)在空间线索任务中,当刺激呈现时间为250ms或500ms时,老年抑郁组与老年正常组的返回抑制效应在各种情绪刺激下均无显著差异(P>0.05),即老年抑郁个体没有呈现出对任何情绪刺激类型的注意偏向现象;当刺激呈现时间为750ms或1000ms时,老年抑郁组的返回抑制效应在不同情绪刺激条件下差异显著,F(2, 66)=3.22,P=0.046,而老年正常组则不存在返回抑制效应在情绪刺激类型上的差异(P>0.05),提示老年抑郁组对不同情绪类型的刺激注意返回抑制能力不同;进一步检验得知:返回抑制效应在悲伤条件下,存在组间差异,分别是F(1, 33)=10.03,P=0.003;F(1, 33)=18.21,P=0.000,即老年抑郁组的返回抑制效应弱于老年正常组。(2)在Stroop实验中,老年抑郁组在单中性、双中性与单悲伤面孔、中性悲伤面孔、双悲伤面孔线索类型下的反应时差异显著;且当线索类型为单悲伤面孔、中性悲伤面孔、双悲伤面孔时,老年抑郁组与老年正常组的反应时差异均显著,即老年抑郁组的反应时明显长于老年正常组,F(1, 41) = 5.37,P=0.026;F(1, 41) = 7.08,P=0.011;F(1, 41) = 7.28,P=0.010;而当线索类型为单中性和双中性面孔时,老年抑郁组与老年正常组的反应时差异不显著(P>0.05);提示抑郁组可能在自动化注意选择分配期存在注意偏向。研究认为,老年抑郁个体的注意偏向可能发生在注意初始分配阶段和解释阶段,且受加工深度的影响。在刺激呈现时间较长的条件下,注意偏向的效应更明显。  相似文献   
134.
部分线索效应指让学习者学习一系列材料, 在随后的测试阶段, 给学习者提供先前所学材料的一部分作为提取线索, 让其回忆剩余的材料, 回忆成绩反而比没有提取线索时回忆成绩差的现象。通过3个实验, 以图片为实验材料, 考察了图片部分线索效应学习时间分配的发展特点。实验1考察了图片部分线索效应的边界条件, 结果发现:图片学习中, 以物体名称为线索时, 不存在部分线索效应; 而以图片为线索时, 存在部分线索效应。结果表明:跨域线索是图片部分线索效应的边界条件。实验2利用图片作线索, 考察了图片部分线索效应的发展特点, 结果发现:图片学习中, 不同年龄被试均存在部分线索效应。结果表明:年龄不是图片部分线索效应的边界条件。实验3考察不同年龄被试对部分线索消极作用的记忆监控的发展变化趋势, 结果发现:小学二年级儿童即使经过多次学习, 也不能意识到部分线索的消极作用; 小学五年级儿童经过二次学习后, 方可意识到这种消极作用, 并在部分线索条件下安排了更多的学习时间; 初二和高二年级学生经过一次学习, 即可意识到部分线索的消极作用, 他们均在部分线索条件下安排了更长的学习时间。结果表明:儿童的学习时间分配决策能力在小学二年级到小学五年级之间有一个质的提高; 与初二学生相比, 高二学生对部分线索带来的消极影响做了更多的时间补偿。  相似文献   
135.
本项目突破了以往研究过于聚焦\"助人行为\"这一瞬时行为的局限,把工作场所中的助人决策理解为一种基于动态性心理契约的社会性风险投资决策过程,认为人力资源管理的相关实践能够在组织内部为员工之间的这种社会性风险投资决策,创建和维持适宜的投资环境,促使员工愿意、能够、敢于进行助人这种社会性风险投资决策。基于上述思路,项目首先构建工作场所中助人决策的过程机制模型,然后就该模型与以往模型存在的核心差异——反思调整——进行深入探索。随后,就影响助人决策投资环境的重要因素,从人力资源管理职能的角度,分别探讨工作设计和薪酬管理两个方面的重要变量对助人决策的影响机制。最后,基于本项目研究成果,提出能切实促进员工助人决策的、体系化的人力资源管理实践建议。  相似文献   
136.
    
We test people's ability to optimize performance across two concurrent tasks. Participants performed a number entry task while controlling a randomly moving cursor with a joystick. Participants received explicit feedback on their performance on these tasks in the form of a single combined score. This payoff function was varied between conditions to change the value of one task relative to the other. We found that participants adapted their strategy for interleaving the two tasks, by varying how long they spent on one task before switching to the other, in order to achieve the near maximum payoff available in each condition. In a second experiment, we show that this behavior is learned quickly (within 2–3 min over several discrete trials) and remained stable for as long as the payoff function did not change. The results of this work show that people are adaptive and flexible in how they prioritize and allocate attention in a dual‐task setting. However, it also demonstrates some of the limits regarding people's ability to optimize payoff functions.  相似文献   
137.
    
Our aims are to (1) set forth a multiprinciple system for selecting among clinical trials competing for limited space in an immunotherapy production facility that supplies products under investigation by scientific investigators; (2) defend this system by appealing to justice principles; and (3) illustrate our proposal by showing how it might be implemented. Our overarching aim is to assist manufacturers of immunotherapeutic products and other potentially breakthrough experimental therapies with the ethical task of prioritizing requests from scientific investigators when production capacity is limited.  相似文献   
138.
本文提出了一种新的并行演化算法――异步异构分层并行演化算法(AHHPGA),用于求解串并系统可靠性分配的多目标优化问题(RAP)。AHHPGA采用分层结构,上层由粗粒度模型构成,下层由细粒度模型构成。在AHHPGA的每个子种群中,采用不同的全局/局部搜索度和拓扑结构,构成异构模型。AHHPGA的迁移方式包括异步接收和异步迁出。采用基于模型的复杂系统可靠性评价工具(HiP-HOPS),以克服可靠性框图方法(RBD)的缺点。仿真结果表明,基于异步异构分层并行演化算法和HiP-HOPS工具的串并系统可靠性分配的多目标优化方法,优于传统的基于遗传算法的优化方法。  相似文献   
139.
In a recent paper in Science and Engineering Ethics (SEE) Elliott proposed an ethics of expertise, providing its theoretical foundation along with its application in a case study devoted to the topic of hormesis. The application is based on a commentary in the journal Nature, and it includes assertions of ethical breaches. Elliott concludes that the authors of the commentary failed to promote the informed consent of decision makers by not providing representative information about alternative frequency estimates of hormesis in the literature, thereby hindering the capacity of the scientific community to promote informed consent relating to chemical regulation. This paper argues that Elliott should have incorporated due process into his system of evaluation. His argument is also seriously deficient technically, in that it misinterprets the toxicological issues, misrepresents the scientific literature with respect to the frequency of hormesis, and incorrectly assesses the extent to which the Nature paper revealed opposing/alternative views on hormesis. Given the seriousness of assertions of noncompliance to ethical norms, there must be procedures to protect those whose ethics were called into question, to fairly evaluate the technical justification for an assertion, and to enable corrections in the event of errors. If a journal is willing to publish assertions that individuals acted in an ethically questionable way, it should be guided by a documented code of ethics and meet a standard of responsibility far greater than normal peer-review processes for papers that do not entail such ethical judgments.  相似文献   
140.
The effects of anxiety upon attention allocation to affective stimuli   总被引:3,自引:0,他引:3  
Pictures of emotionally aversive, neutral, and pleasant scenes were presented for 500 ms, followed by a probe presented in the same location (valid trials) or an alternate location (invalid trials) as the picture. Response-times to the probes were recorded in low (N=20) and high (N=27) trait anxious participants. Results revealed an overall negative cue validity effect of shorter reaction times (RTs) on invalid than valid trials, suggestive of an inhibition of return effect. Moreover, high trait anxious females showed a reduced negative cue validity effect for aversive pictures in comparison with neutral and pleasant pictures, suggestive of selective interference by the unpleasant material. By contrast, low trait anxious females showed an enhanced negative cue validity effect for aversive pictures relative to neutral and pleasant pictures, suggestive of attentional avoidance of the aversive content. The emotional content of picture cues did not significantly affect RTs in males, regardless of anxiety status. The results suggest that biased attention processes for aversive stimuli may contribute to the greater female propensity for anxiety disorders.  相似文献   
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