Perceptual space in the dark affected by the intrinsic bias of the visual system

Correct judgment of egocentric/absolute distance in the intermediate distance range requires both the angular declination below the horizon and ground-surface information being represented accurately. This requirement can be met in the light environment but not in the dark, where the ground surface is invisible and hence cannot be represented accurately. We previously showed that a target in the dark is judged at the intersection of the projection line from the eye to the target that defines the angular declination below the horizon and an implicit surface. The implicit surface can be approximated as a slant surface with its far end slanted toward the frontoparallel plane. We hypothesize that the implicit slant surface reflects the intrinsic bias of the visual system and helps to define the perceptual space. Accordingly, we conducted two experiments in the dark to further elucidate the characteristics of the implicit slant surface. In the first experiment we measured the egocentric location of a dimly lit target on, or above, the ground, using the blind-walking-gesturing paradigm. Our results reveal that the judged target locations could be fitted by a line (surface), which indicates an intrinsic bias with a geographical slant of about 12.4 degrees. In the second experiment, with an exocentric/relative-distance task, we measured the judged ratio of aspect ratio of a fluorescent L-shaped target. Using trigonometric analysis, we found that the judged ratio of aspect ratio can be accounted for by assuming that the L-shaped target was perceived on an implicit slant surface with an average geographical slant of 14.4 degrees. That the data from the two experiments with different tasks can be fitted by implicit slant surfaces suggests that the intrinsic bias has a role in determining perceived space in the dark. The possible contribution of the intrinsic bias to representing the ground surface and its impact on space perception in the light environment are also discussed.     

Binocular rivalry and surface-boundary processing

Theoretical and empirical studies show that the visual system relies on boundary contours and surface features (e.g. textures) to represent 3-D surfaces. When the surface to be represented has little texture information, or has a periodic texture pattern (grating), the boundary contour information assumes a larger weight in representing the surface. Adopting the premise that the mechanisms of 3-D surface representation also determine binocular rivalry perception, the current paper focuses on whether boundary contours have a similar role in binocular rivalry. In experiment 1, we tested the prediction that the visual system prefers selecting an image/figure defined by boundary contours for rivalry dominance. We designed a binocular rivalry stimulus wherein one half-image has a boundary contour defined by a grating disk on a background with an orthogonal grating orientation. The other half-image consists solely of the (same orientation) grating background without the grating disk, ie no boundary contour. Confirming our prediction, the predominance for the half-image with the grating disk is approximately 90%, despite the fact that the grating disk corresponds to an area with orthogonal grating in the fellow eye. The advantage of the grating disk is dramatically reduced to about 50% predominance when a boundary contour is added to the background-only half-image at the location corresponding to the grating disk. We attribute this reduced advantage to the formation of a corresponding binocular boundary contour. In experiment 2 the grating background was substituted by a random-dot background in a similar stimulus design. We found that the perceptual salience of the corresponding binocular boundary contours extracted by the interocular matching process is an important factor in determining the dynamics of binocular rivalry. Experiment 3 showed that vertical lines with uneven thickness and spacing as the background reduce the contribution of the monocular boundary contour of the grating disk in binocular rivalry, possibly through the formation of binocular boundary contours between the local edges (vertical components) of the vertical lines and the corresponding grating disk.     

Effects of hippocampal injections of a novel ligand selective for the alpha 5 beta 2 gamma 2 subunits of the GABA/benzodiazepine receptor on Pavlovian conditioning

Benzodiazepine pharmacology has led to greater insight into the neural mechanisms underlying learning and anxiety. The synthesis of new compounds capable of modulating responses produced by these receptors has been made possible by the development of an isoform model of the GABA(A)/benzodiazepine receptor complex. In the current experiment, rats were pretreated with several concentrations of the novel ligand RY024 (an alpha 5 beta 2 gamma 2 -selective benzodiazepine receptor inverse agonist) in the hippocampus and were trained in a Pavlovian fear conditioning paradigm. RY024 independently produced fear-related behavior prior to training and, at the highest concentration, decreased the strength of conditioning observed 24 h after training. These data provide further evidence for the involvement of hippocampal GABA(A)/benzodiazepine receptors in learning and anxiety.     

Elderly suicide in China

The rise in suicide rate among elderly people in China in recent years is noteworthy and may be associated with the increasing poverty of elderly people and the lack of social resources allocated to providing them with needed services to ensure their health and mental well-being.     

Twin-coupled domain structures in epitaxial relaxor ferroelectric Ba(Zr,Ti)O3 thin films on (001) MgO substrate

We report the twin-coupled multi-oriented domain structures in the epitaxial BZT20 (20%Zr) films grown on the (001) MgO substrate using pulsed-laser deposition. Transmission electron microscopy shows that the film consists of an epitaxial layer of pseudo-cubic perovskite structure and a nanopillar layer of multi-oriented twin domain structures near the surface. Four types of the twin domains were formed in the nanopillar layers by coherently joining their {111} with the epilayer and aligning their ?110? directions parallel to the ?110? axes of the epilayer. A non-uniform polarization switching behavior was observed due to the formation of such complex structure in the BZT20 films.     

On the orientation relationship between a2 precipitates and the B2 phase in a Ti-47at.%Al-2at.%W-0.5at.%Si alloy

An k -phase Mn-Al-C single crystal was grown and annealed to obtain an intermediate stage of the k M transformation. The crystal was analysed by transmission electron microscopy, and direct evidence for the operation of the shear mode was obtained. The transformation occurs in two steps from the hcp structure ( k ) over the orthorhombic structure ( k ' phase) to the tetragonal phase. The study reveals the morphologies of k ' and , the necessity for reordering during the second transformation step ( k ' M ) which is not a purely martensitic transformation, and the selection of variants which is controlled by stresses through the selection of one k ' variant.     

中学生学习倦怠与未来时间洞察力、成就目标取向的关系

采用问卷调查法对989名中学生进行施测,探讨了学习倦怠及其与未来时间洞察力和成就目标趋向的关系.结果发现:(1)未来时间洞察力与成绩趋近、掌握趋近和掌握回避有显著的正相关,并具有显著的预测作用:未来时间洞察力与成绩回避取向和学习倦怠具有显著的负相关,并具有显著的预测作用; (2)掌握趋近取向与学习倦怠具有显著的负相关,并有预测作用:成绩回避和掌握回避与学习倦怠有显著的正相关,并具有显著的预测作用; (3)掌握趋近、成绩回避和掌握回避取向在未来时间洞察力与学习倦怠之间有部分中介作用.     

北京实验动物从业人员对动物福利认知的问卷调查

北京市实验动物从业人员动物福利问题问卷调查显示,因疏忽、无知导致伤害实验动物的情况仍然存在,实验动物从业人员对动物福利问题的认知情况不容乐观.值得欣慰的是,绝大多数实验动物从业人员在对待实验动物福利问题的态度上,显示了对实验动物的关注、对生命的珍惜和关怀.为推动实验动物福利建设,促进我国生命科学健康发展,应加强实验动物从业人员培训教育,树立动物福利意识,推进实验动物福利立法进程及实验动物福利体系建设.     

父母亲职压力与儿童对立违抗行为的关系:一项交叉滞后分析

采用亲职压力量表和对立违抗行为表现评估表调查了来自北京、山东和云南三地14所小学有ODD(oppositional defiant disorder)行为表现的301名儿童及其父母。通过为期两年的追踪研究,采用交叉滞后分析探讨了父母亲职压力与儿童的ODD行为之间的关系。结果发现:(1)在第一年和第二年的数据中,父母亲职压力和儿童的ODD行为表现均存在显著正相关;(2)第一年和第二年的父母亲职压力得分显著正相关,同样,两年的儿童ODD行为表现得分也显著正相关;(3)交叉滞后分析发现,对于有ODD行为表现的男孩来说,其父母第一年的亲职压力能预测他们第二年的ODD行为表现,但对于有ODD行为表现的女孩来说,其父母第一年的亲职压力并不能预测她们第二年的ODD行为表现;而不管是男孩,还是女孩,第一年的ODD行为表现都不能预测第二年的父母亲职压力。研究结果揭示出男孩父母的亲职压力可预测男孩的ODD行为表现,而不论是男孩或女孩的ODD行为表现都不能预测其父母亲职压力,说明父母亲职压力可能是男孩ODD行为表现的影响因素。     

认知冲突协调问题与心智的架构

心智架构或认知架构是指一个功能相对完整的认知系统的基本组织结构。经典认知科学的理论或模型大多采纳了某种类似于冯·诺依曼式计算机体系结构的心智架构,即认知系统由一些各司其职的心理模块与一个负责整合与协调的中枢部门所构成。进化心理学的众量模块性论题对经典认知科学的心智架构观提出了严厉挑战,并引发了许多争议。本文提出认知冲突协调问题是任何一个足够复杂的认知系统均需要处理的基本问题,并以此来审视关于心智架构的论战,指出此问题对众量模块性论题构成了严重的困难。