Determination of the depth distribution of subsurface damage during polishing of alumina

High-resolution grazing-incidence parallel-beam powder diffraction has been used to detect the subsurface damage below alumina surfaces subjected to polishing with cerium oxide or diamond. Despite very significant evolution of the surface morphology, no changes in the subsurface strains were observed over a 20min period of polishing with ceria. For both polishing materials, the variation with angle in the full-width at half-height maximum was successfully modelled by a strain distribution that fell exponentially with increasing depth. Although the surface amplitude and depth dependence parameter are coupled, we have been able to place upper limits on the depth to which the damage extends. Under realistic assumptions, the depth of damage induced by 1µm diamond paste is comparable with that from 3µm ceria polish.     

The orientation and temperature dependences of dislocation velocity in Ni 3 Al single crystals

The average velocities of screw dislocations in Ni 3 Al single crystals have been directly measured as a function of resolved shear stress (RSS) and orientation in the temperature domain of the flow stress anomaly using the etch-pit technique. The velocity was found to be extremely sensitive to the RSS in all cases. In contrast with ordinary metals, the screw dislocation velocities in Ni 3 Al show anomalous behaviour; under a constant RSS, the velocities decrease dramatically with increasing temperature. Furthermore, the velocities and the tension-compression asymmetry of the velocities depend on the orientation of applied stress.     

Prevalence and Predictors of Posttraumatic Growth in Accidentally Injured Patients

This study examined prevalence and predictors of posttraumatic growth in 180 accidentally injured patients of mainland China in their convalescence stage, investigating its relationships with demographic and accidental injury variables, personality, posttraumatic stress disorder (PTSD) symptoms, and coping styles. Our results showed that posttraumatic growth (PTG) presented mostly in the domain of Relating to Others and indicated that PTG was significantly related to marital status, educational level, personality, coping styles, and PTSD symptoms. Avoidance of PTSD symptoms, Openness to experience, and positive coping were significant predictors of PTG. The findings emphasize that when promoting PTG of accidentally injured patients, healthcare providers should facilitate patients utilizing personal resources, understand PTG coexists with PTSD symptoms, and adjust interventions based on the coping styles the patients have adopted.     

Perceptual constraints on implicit learning of spatial context

If perspective views of an object in two orientations are displayed in alternation, observers will experience the object rotating back and forth in three-dimensional space. Rotational motion is perceived even though only two views are displayed and each view is two-dimensional. The results of 5 experiments converge on the conclusion that the perception of apparent rotational motion produces representations in visual memory corresponding to the spatial structure of the object along its arc of rotation. These representations are view-dependent, preserving information about spatial structure from particular perspectives, but do not preserve low-level perceptual details of the stimulus.     

Mind-reading without the scanner: Behavioural decoding of working memory content

ABSTRACT

Sophisticated machine learning algorithms have been successfully applied to functional neuroimaging data in order to characterize internal cognitive states. But is it possible to “mind-read” without the scanner? Capitalizing on the robust finding that the contents of working memory guide visual attention toward memory-matching objects, we trained a multivariate pattern classifier on behavioural indices of attentional guidance. Working memory representations were successfully decoded from behaviour alone, both within and between individuals. The current study provides a proof-of-concept for applying machine learning techniques to simple behavioural outputs (e.g., response times) in order to decode information about specific internal cognitive states.     

Play it again: neural responses to reunion with excluders predicted by attachment patterns

Reunion behavior following stressful separations from caregivers is often considered the single most sensitive clue to infant attachment patterns. Extending these ideas to middle childhood/early adolescence, we examined participants' neural responses to reunion with peers who had previously excluded them. We recorded event‐related potentials among nineteen 11‐ to 15‐year‐old youth previously classified on attachment interviews (11 secure and 8 insecure‐dismissing) while they played a virtual ball‐toss game (Cyberball) with peers that involved fair play, exclusion and reunion phases. Compared to secure participants, dismissing participants displayed a greater increment in the N2 during reunion relative to fair play, a neural marker commonly linked to expectancy violation. These data suggest a greater tendency toward continued expectations of rejection among dismissing children, even after cessation of social exclusion. In turn, the link between self‐reported ostracism distress and neural signs of negative expectancy at reunion was moderated by attachment, such that self‐reports were discordant with the neural index of expectancy violation for dismissing, but not for secure children. A video abstract of this article can be viewed at http://www.youtube.com/watch?v=qzoRel5c-4s .     

两例先天性无痛症患者的心理生理特点研究 Ⅱ.对致痛性强刺激的知觉和反应

本工作对两例先天性无痛症患者对于致痛性强刺激的知觉和反应进行了研究(例1女,10岁,例2男,13岁)。对照组为20例正常儿童,性别和年龄均与患儿相匹配。 结果:1),生活中痛:两例患儿均无(包括痛感觉和痛反应)。2)实验性痛:①痛感觉:两例患儿均无;②“痛”反应:例1有“痛”反应(脉搏和呼吸的变化以及行为反应明显,大致与正常儿童相似)。例2无“痛”反应(脉搏和呼吸的变化轻微,无行为反应,与正常儿童不同)。 由结果看来,先天性无痛症患者似乎可分为两种类型:不完全型(如同例1)和完全型(如同例2)。存在有“痛”反应而无痛感觉的无痛症患者。 本工作结果从另一侧面为痛的两成分学说提供了依据。     

词频和年级对FOK判断的影响

本实验以识记材料的词频高低和被试年级为自变量对被试元记忆监测的FOK(feeling of knowing)判断进行研究。实验采用Hart提出的RJR(回忆—FOK判断—标准测验 )的经典范式。结果表明 :被试的年级影响FOK判断等级和准确性 ,大学生的FOK判断等级和准确性均高于高一年级学生 ;识记材料词频影响FOK判断等级的高低 ,不影响FOK判断准确性 ,被试对高频词对的FOK判断等级高于对低频词对的FOK判断等级 ,但FOK判断准确性无明显差异。     

汉语词类歧义解决初探

采用自定步速移动窗口阅读实验范式,考察汉语词类歧义解决过程。阅渎材料为含有单字词类歧义词的句子,歧义词前面的语境不提供明确的偏向性信息．后语境提供解歧信息。结果发现,主要用法和次要用法的句子都在解歧区比控制句阅读时间加长,表明汉语词类歧义解决没有即时受到歧义词两种用法的相对频率影响,而是在歧义词处暂时不进行完全的句法分配,延迟到获得充分解歧信息的时候才分配句法角色。这一结果支持词类歧义解决的延迟模型。     

IAT效应在不同目标概念水平上的差异研究

采用IAT实验设计,考察大学生对不同概念词的内隐态度之间的差别。结果发现,八组实验材料都产生了显著的IAT效应;不同性别的测验材料的IAT效应间不存在显著差异,不同喜好程度的测验材料的IAT效应间存在显著差异,且两个因素存在显著的交互作用。研究表明,IAT效应既可在上位概念水平上产生,亦可在下位概念水平上产生。