颞叶皮层在灵长类不变性知觉和原型表征中的重要作用

如果要走出人工智能在感知觉领域的困境．就必须认识到人类特有的受生物现实约束的认知特点。综合分析各种证据表明,知觉和客体识别的本质不是分析千差万别的局部特征,而是提取环境中的大范围不变量（早期为拓扑特性检测）,形成并存贮一定原型表征;颞叶皮层在灵长类这种不变性知觉和原型表征中具有重要作用。     

Detection and discrimination of optical flow components

Observers viewed animation sequences consisting of random dots, some of which moved coherently in a given direction (signal dots) and the rest of which moved randomly (noise dots). Using forced-choice procedures, detectability of weak signals within noise was measured for translation, rotation, and expansion/contraction. Sensitivity to all motion types was approximately equal, with practiced observers reliably detecting coherent motion at signal levels as low as 4%. Observers were able to identify the motion structure presented on a given trial at signal levels corresponding to the detection threshold, implying that the neural signals supporting detection are labeled for motion type. Results are discussed in the context of hierarchical analysis of optic flow in which all motion types are registered as patterns of activity among neurons comprising a single mechanism.     

Cardiovascular and neuroendocrine activity in preschool children: Comparison between day-care and home levels

Thirty boys and 30 girls at nine day-care centers were examined at the mean age of 3.5 and 5.5 with regard to systolic and diastolic blood pressure, heart rate and neuroendocrine activity (urinary catecholamines and cortisol) during a day at their day-care center and in their home, respectively. Compared to home levels, day-care was associated with increased heart rate, epinephrine and norepinephrine excretion and decreased cortisol levels. Systolic blood pressure decreased at the day-care centers at the age of 3.5 and increased at the age of 5.5. No significant sex differences were found. The possible role of mental and physical arousal and the dissociation between the sympathetic-adrenal medullary and the pituitary-adrenal cortical responses are discussed.     

KNOWING WHEN TO SAY WHEN: A SIMPLE ASSESSMENT OF ALCOHOL IMPAIRMENT

The use of writing samples as indices of alcohol impairment was explored. Students at a campus fraternity party wrote a sentence and their signatures before and after consuming alcohol (in beer and mixed drinks). Later, undergraduate and graduate students attempted to discriminate between pre- and postparty handwriting samples. The average percentage of correct discriminations of entrance and exit writing samples was 83.7% for sentences and 67.5% for signatures, and the percentage of correct discriminations increased directly with the blood alcohol concentration of the partier who gave the writing sample. When a partier's blood alcohol concentration reached 0.15, all of the judges accurately discriminated 90% or more of the sentences, and 25 of the 28 judges correctly discriminated at least 80% of the signatures. All of the judges correctly discriminated at least 90% of the 18 sentences written by partiers with a blood alcohol concentration of 0.12 or more. Implications of these findings for reducing the risk of driving while intoxicated are discussed, as well as directions for follow-up research.     

脐血干细胞移植中的伦理思考

现代干细胞移植技术飞速发展。脐血干细胞移植在伦理学上具有胚胎干细胞和骨髓干细胞移植治疗不可比拟的优势,但是其伦理学上的可接受性并不等于伦理问题的消失。在脐血干细胞移植研究过程中,应该遵循伦理道德观和科学理性的原则,健康发展,造福人类。     

慢性乙型肝炎患者外周血中睾酮的变化及其意义

测定65例慢性乙型肝炎患者和35例健康者血清睾酮水平,并分别检测血清丙氨酸氨基转移酶（alanine aminotransferase,ALT）、谷氨酸氨基转移酶（aspartate aminotransferase,AST）、γ-谷氨酰基转肽酶（gamma-glutamyl transpeptidase,GOT）、血清总胆红素（total bilirubin,TBIL）、碱性磷酸酶（alkaline phosphatase,ALP）、免疫球蛋白IgG、IgM、IgA,荧光定量PCR检测外周血HBV DNA水平。慢性乙型肝炎患者血清睾酮水平显著高于正常对照组,HBeAg阳性患者较HBeAg阴性患者升高明显,但差别无显著意义。慢性乙型肝炎患者肝功血清学指标ALT、AST、TBIL、GGT、ALP及IgG水平显著高于正常人,但乙肝患者睾酮水平与ALT等生化指标及HBV DNA水平无明显相关性,与免疫球蛋白IgG呈中等负相关。因而可以看出慢性乙型肝炎患者血清睾酮水平显著高于正常人,睾酮水平升高可作为慢性乙型肝炎的易感因素之一。     

Role of motivation,self‐efficacy and parent support in adolescent structured leisure activity participation

An increasing body of research supports the positive physical, social and psychological health benefits of adolescent involvement in structured out‐of‐school leisure activities. Analysis of data from 1280 12–17‐year‐old Western Australian metropolitan high school students, found that several factors were associated with adolescent involvement in structured leisure activities, including parent support of the activity (both active and passive), intrinsic motivation and self‐efficacy. There were no significant gender differences in the rate of participation or hours spent participating in structured leisure activities overall. More female than male students, however, were involved in structured creative activities and male students spent significantly more time involved in structured physical group activities. Recommendations for supporting adolescent involvement in structured leisure activities are discussed.     

A neural model of how the brain computes heading from optic flow in realistic scenes

Visually-based navigation is a key competence during spatial cognition. Animals avoid obstacles and approach goals in novel cluttered environments using optic flow to compute heading with respect to the environment. Most navigation models try either explain data, or to demonstrate navigational competence in real-world environments without regard to behavioral and neural substrates. The current article develops a model that does both. The ViSTARS neural model describes interactions among neurons in the primate magnocellular pathway, including V1, MT⁺, and MSTd. Model outputs are quantitatively similar to human heading data in response to complex natural scenes. The model estimates heading to within 1.5° in random dot or photo-realistically rendered scenes, and within 3° in video streams from driving in real-world environments. Simulated rotations of less than 1°/s do not affect heading estimates, but faster simulated rotation rates do, as in humans. The model is part of a larger navigational system that identifies and tracks objects while navigating in cluttered environments.     

When Walking Makes Perception Better

ABSTRACT— When we move, the visual world moves toward us. That is, self-motion normally produces visual signals (flow) that tell us about our own motion. But these signals are distorted by our motion: Visual flow actually appears slower while we are moving than it does when we are stationary and our surroundings move past us. Although for many years these kinds of distortions have been interpreted as a suppression of flow to promote the perception of a stable world, current research has shown that these shifts in perceived visual speed may have an important function in measuring our own self-motion. Specifically, by slowing down the apparent rate of visual flow during self-motion, our visual system is able to perceive differences between actual and expected flow more precisely. This is useful in the control of action.     

乙脑患儿血清神经元特异性烯醇化酶、S-100蛋白、髓鞘碱性蛋白测定及其临床意义

为了解流行性乙型脑炎（乙脑）患儿血清神经元特异性烯醇化酶（NSE）、S-100蛋白（S-100）、髓鞘碱性蛋白（MBP）含量变化及其临床意义,用酶联免疫吸附法检测100例乙脑患儿血清NSE、S-100、MBP含量变化。结果显示,乙脑组患儿血清NSE、S-100、MBP含量与对照组比较显著增高（P均〈0．01）,增高程度与病情严重程度相平行（P〈0．01）。因此,血清NSE、S-100、MBP含量测定对乙脑患儿脑损伤严重程度及临床预后判断有重要参考价值。