Reward Influence on the Heart: Cardiovascular Response as a Function of Incentive Value at Five Levels of Task Demand

This study examined cardiovascular effects of incentive value in men and women confronted with cognitive challenges that were more and less difficult to meet. Participants performed computer memory tasks varying in difficulty from low to high, with instructions that they could earn chances toward a $100 prize or $10 prize by attaining a 90% success rate. Analysis of cardiovascular responses assessed during work revealed an interaction between difficulty and incentive value for heart rate. Participants' heart rate responses were proportional to task difficulty and unaffected by incentive value in all conditions except for the most difficult one. Where difficulty was greatest, $100 participants showed relatively high heart rate responsiveness, whereas $10 participants showed low heart rate responsiveness. This heart rate finding corroborates and extends cardiovascular results from previous experiments, and lends further support to the view that cardiovascular responses will be proportional to incentive value only under some task conditions.     

Intelligence and neural efficiency: The influence of task content and sex on the brain–IQ relationship

In studying physiological correlates of human intelligence, new brain imaging techniques like positron emission tomography (PET) and electroencephalography (EEG) mapping methods focus on the level and topographical distribution of cortical activation. Actually, there is strong empirical evidence that more intelligent individuals display a more focused cortical activation during cognitive performance resulting in lower total brain activation than in less intelligent individuals (i.e., neural efficiency hypothesis). Former studies have used only single, homogeneous tasks and most of the studies have been performed using males. Therefore, here the influence of different task content and of sex on the relationship between intelligence and cortical activation has been tested. In a sample of 26 males and 25 females, we administered verbal, numerical, and figural versions of a well-known elementary cognitive task, the so-called Posner task. Our results suggest a comparatively low cortical activation in brighter as compared to less intelligent individuals but this expected neural efficiency pattern interacted with sex and task content: In the verbal Posner task, the females were more likely to produce cortical activation patterns in line with the neural efficiency hypothesis, whereas in the figural task, primarily the males displayed the expected inverse relationship between IQ and cortical activation.     

Does well‐being contribute to performance? Emotional security,teacher support and learning behaviour in kindergarten

In this study, we examined relations between kindergartner's emotional security, task involvement and achievement and teacher's supportive presence in a cognitive training setting, in which the familiarity of the teacher was varied. Participants were 48 kindergarten children (mean age=51.65 months); 16 children were trained by their regular teacher (experimental group 1), 16 by a less familiar teacher (experimental group 2) and 16 received no training (control group). In three training sessions, children worked in pairs on a new categorization and recall task. Trained observers rated children's emotional insecurity and task involvement and teacher's supportive presence. Furthermore, spontaneous recall during the training was assessed. In addition, categorization and spontaneous recall was measured in various test sessions. Children's emotional insecurity during training negatively affected involvement. Involvement on its turn positively influenced spontaneous recall during training. In addition, emotional insecurity had a direct negative effect on spontaneous recall in a test situation. No effect of familiarity or supportive presence of the teacher on emotional security was found. Training conditions did not affect test performances. Findings suggest that children's involvement is important for learning and that experiences of emotional insecurity may negatively affect task involvement, test performance and eventually school achievement. Teachers in general seem capable of providing children with some sense of security. Copyright © 2004 John Wiley & Sons, Ltd.     

短期学习对陌生面孔认知绩效的影响

本文研究了不同的短期学习时间对陌生面孔的绝对辩认绩效的影响。结果表明：(1)0．5分、1分、5分这三种不同的短期学习时间对陌生面孔的绝对辩认绩效没有明显的影响。(2)人们对人脸结构信息的改变非常敏感,当结构信息变动4．88个象素(或9．13’)时,被试对陌生面孔的平均正确绝对辩认率可达到75％以上。(3)在对陌生人脸的绝对辩认中,被试的正确辩认率随着结构信息变化量的增加而提高,趋势分为快速增长区和迟滞增长区两个区域。     

关于RB效应加工水平的研究

本研究采用正字法相似的汉字作为实验材料考察了RSVP任务中的RB效应的加工水平。研究发现：(1)RB效应不仅出现在重复字中,而且也出现在正字法相似字中,但其强度弱于重复字中的RB效应;(!)在正字法相似的汉字加工中．由于加工相似字的识别错误发生在语义加工之前的阶段．因此．RB效应的产生点可能出现在记忆加工之前的知觉阶段。     

Dual scaling of comparison and reference stimuli in multi-dimensional psychological space

Dzhafarov and Colonius (Psychol. Bull. Rev. 6 (1999)239; J. Math. Psychol. 45(2001)670) proposed a theory of Fechnerian scaling of the stimulus space based on the psychometric (discrimination probability) function of a human subject in a same-different comparison task. Here, we investigate a related but different paradigm, namely, referent-probe comparison task, in which the pair of stimuli (x and y) under comparison assumes substantively different psychological status, one serving as a referent and the other as a probe. The duality between a pair of psychometric functions, arising from assigning either x or y to be the fixed reference stimulus and the other to be the varying comparison stimulus, and the 1-to-1 mapping between the two stimulus spaces X and Y under either assignment are analyzed. Following Dzhafarov and Colonius, we investigate two properties characteristic of a referent-probe comparison task, namely, (i) Regular cross-minimality—for the pair of stimulus values involved in referent-probe comparison, each minimizes a discrimination probability function where the other is treated as the fixed reference stimulus; (ii) Nonconstant self-similarity—the value of the discrimination probability function at its minima is a nonconstant function of the reference stimulus value. For the particular form of psychometric functions investigated, it is shown that imposing the condition of regular cross-minimality on the pair of psychometric functions forces a consistent (but otherwise still arbitrary) mapping between X and Y, such that it is independent of the assignment of reference/comparison status to x and to y. The resulting psychometric differentials under both assignments are equal, and take an asymmetric, dualistic form reminiscent of the so-called divergence measure that appeared in the context of differential geometry of the probability manifold with dually flat connections (Differential Geometric Methods in Statistics, Lecture Notes in Statistics, Vol. 28, Springer, New York, 1985). The pair of divergence functions on X and on Y, respectively, induce a Riemannian metric in the small, with psychometric order (defined in Dzhafarov & Colonius, 1999) equal to 2. The difference between the Finsler-Riemann geometric approach to the stimulus space (Dzhafarov & Colonius, 1999) and this dually-affine Riemannian geometric approach to the dual scaling of the comparison and the reference stimuli is discussed.     

课堂情境与任务难度对学业求助之影响的研究

本实验以初二年级学生为被试,研究了课堂情境、任务难度、学业成绩以及性别对学业求助的影响。结果表明：(1)任务关注的课堂情境比自我关注的课堂情境导致更多的求助行为,求助方式上,则倾向于工具性求助。(2)完成难度适中学习任务的学生比完成高难度学习任务的学生表现出更多的求助行为,求助方式上,则倾向于工具性求助。(3)在任何条件下,成绩好的学生都比成绩差的学生更善于作工具性求助。(4)从总体来看,初二学生的求助行为不存在性别差异。但在自我关注的课堂中,男生比女生表现出更多的回避求助。     

自主任务转换中的重构和干扰

任务转换是研究执行功能的常用范式。任务转换通常伴随着转换代价：执行转换任务比重复任务的反应时更长、错误率更高。转换代价可能反映了任务设置重构(重构理论), 也可能表明任务之间存在干扰(干扰理论)。与任务线索范式相比, 自主任务转换范式更具生态效度, 而且不仅能获得转换代价这个传统结果, 还引入了任务选择比例、任务转换率等新指标, 其结果倾向于支持重构理论。此外, 新近研究指出自主任务转换可能也包含干扰的作用。未来, 应通过进一步改进实验范式等方法, 实现两大理论的融合。     

无意识信息的刺激表征及其时间特性

无意识信息是否存在刺激表征有待解决。实验采用字母Flanker任务, 通过目标和flanker在刺激水平和反应水平上的冲突效应, 重点考察阈下flanker在刺激水平的表征。在相同的实验设计下, flanker可觉察时(实验1A), 观察到经典的刺激冲突效应和反应冲突效应; 而flanker无意识时(实验1B), 重复了反应冲突效应, 却观察到刺激冲突效应发生反转, 提示了无意识信息的反应加工及刺激加工。实验2采用符号材料促使刺激−反应的自动联结, 减少刺激−反应规则的难度, 结果重复了实验1B的发现--无意识信息引起反转的刺激冲突。刺激冲突下反转效应的一致结果表明无意识信息的刺激表征影响了认知加工。实验3考察这种影响在时间进程上的特点。无意识刺激表征的影响随反应时变化：在快速反应中观察到刺激冲突效应, 之后该效应发生反转且反转量随反应时增加而增大。相反, 无意识反应表征的影响在不同反应时下保持稳定。以上结果提供了无意识信息存在刺激表征的行为学证据并揭示了其时间特性, 提供了无意识领域中不一致研究结果的整合思路。     

The effects of presentation time on preference for curvature of real objects and meaningless novel patterns

Objects with curved contours are generally preferred to sharp‐angled ones. In this study, we aim to determine whether different presentation times influence this preference. We used images of real objects (experiment 1) and meaningless novel patterns (experiment 2). Participants had to select one of two images from a contour pair, curved and sharp‐angled versions of the same object/pattern. With real objects, the preference for curved versions was greatest when presented for 84 ms, and it faded when participants were given unlimited viewing time. Curved meaningless patterns were preferred when presented for 84 and 150 ms. However, in contrast to real objects, preference for meaningless patterns increased significantly in the unlimited viewing time condition. Participants discriminated poorly between the two versions (curved and sharp‐angled) of the meaningless patterns in the 84‐ and 150‐ms presentations (experiment 3). Therefore, in short times with meaningless patterns, participants selected mostly the curved version without being aware of the difference. In conclusion, presentation time, type of stimulus, and their interaction influence preference for curvature.