Thiamin deprivation in ventromedial hypothalamic hyperphagic rats: anorexia, specificity of food aversion, and a dietary consideration.

The anorexic consequence of thiamin deprivation was investigated in ventromedial hypothalamic (VMH) hyperphagic rats under either high-fat or low-fat thiamin-free diet conditions. The low-fat diet maintained feeding significantly longer in thiamin-deprived VMH rats than in intact rats, whereas the hig-fat diet sustained feeding in thiamin-deficient intact rats and accelerated anorexia onset in vitamin B1 deprived VMH rats. This effect was noted under both ad lib and pair-feeding conditions. Thiamin-deprived VMH rats subjected to weight control developed anorexia sooner than intact subjects regardless of the diet employed. The VMH rats fed a high-fat diet failed to resume feeding after thiamin readministration, which was interpreted as a permanent aversion to this diet. The relation between dietary intake and conditioned taste aversion is discussed with reference to the VMH and intact rat.     

Age-related differences and the role of augmented visual feedback in learning a bimanual coordination pattern

The purpose of this study was to investigate the effects of aging and the role of augmented visual information in the acquisition of a new bimanual coordination pattern, namely a 90° relative phase pattern. In a pilot study, younger and older adults received augmented visual feedback in the form of a real-time orthogonal display of both limb movements after every fifth trial. Younger adults acquired this task over three days of practice and retained the task well over periods of one week and one month of no practice while the older adults showed no improvement at all on the task. It was hypothesized that the amount of augmented information was not sufficient for the older adults to overcome the strong tendency to perform natural, intrinsically stable coordination patterns, which consequently prevented them from learning the task. The present study evaluated the age-related role of augmented visual feedback for learning the new pattern. Participants were randomly assigned within age groups to receive either concurrent or terminal visual feedback after every trial in acquisition. In contrast to the pilot study, all of the older adults learned the pattern, although not to the same level as the younger adults. Both younger and older adults benefitted from concurrent visual feedback, but the older adults gained more from the concurrent feedback than the younger adults, relative to terminal feedback conditions. The results suggest that when learning bimanual coordination patterns, older adults are more sensitive to the structure of the practice conditions, particularly the availability of concurrent visual information. This greater sensitivity to the learning environment may reflect a diminished capacity for inhibitory control and a decreased ability to focus attention on the salient aspects of learning the task.     

The development of spatial understanding in infancy

This paper examines the development of spatial understanding between 8 and 24 months. In particular, it examines whether young infants code changes in the position of an object or themselves in geographic or egocentric terms. The infants sat in a baby chair which was attached to a circular table in such a way that either the infant could be rotated around the edge of the table or the table-top itself could be rotated. Rotation of infant or table could be performed independently or simultaneously. Infants were shown an object which was then hidden under one of either two or three identical cups sitting on the table. Before the infant was allowed to search for the toy, either the table, the infant, or both were rotated, a procedure which resulted in an invisible displacement of the object in terms of geographical and/or egocentric spatial position. Rotations of 60, 90, 120, and 180° were used. Three groups of infants were tested, one cross-sectional (12–24 months), one longitudinal (12–24 months), and one consisting of a group of infants already known to be accelerated in object concept development (8–20 months). The cross-sectional results indicated that egocentric responding continues well into the second half of the second year of life. Even with fortnightly exposure to the tasks, egocentric responding was still evident in some longitudinal babies as late as 19 months. The results of the accelerated group suggest that acceleration through the sequence of object concept development facilitates development of spatial understanding in a wider sense, that is, in the sense of understanding the interrelation of positions in space. The implications of these results for competing theories of the source of object concept errors are discussed.     

Modelling the stages of the identity theory of object-concept development in infancy

A computational model is presented for the three stages of development of the object concept in infancy identified by Bower and Wishart in their research. The stages are described by sets of PROLOG clauses that interpret object structures representing the perceptual phenomena interpreted by the infants themselves. The infant's changes between developmental stages can be described by differences between the rules modelling each stage. Three experiments are presented and the behaviour of the PROLOG model is described for each stage of development. Motion, rest, and boundedness of objects constitute the theoretical underpinning of the running PROLOG model and are hypothesized as the invariant aspects of perception that explain the behaviour of the infant at each stage of development. A possible explanation for transitions between stages is offered and justified in part by the output of the model, which in turn is used to predict the behavioural outcome of an experiment.     

Differential Memory Test Sensitivity for Diagnosing Amnestic Mild Cognitive Impairment and Predicting Conversion to Alzheimer's Disease

ABSTRACT

Episodic memory is the first and most severely affected cognitive domain in Alzheimer's disease (AD), and it is also the key early marker in prodromal stages including amnestic mild cognitive impairment (MCI). The relative ability of memory tests to discriminate between MCI and normal aging has not been well characterized. We compared the classification value of widely used verbal memory tests in distinguishing healthy older adults (n = 51) from those with MCI (n = 38). Univariate logistic regression indicated that the total learning score from the California Verbal Learning Test-II (CVLT-II) ranked highest in terms of distinguishing MCI from normal aging (sensitivity = 90.2; specificity = 84.2). Inclusion of the delayed recall condition of a story memory task (i.e., WMS-III Logical Memory, Story A) enhanced the overall accuracy of classification (sensitivity = 92.2; specificity = 94.7). Combining Logical Memory recognition and CVLT-II long delay best predicted progression from MCI to AD over a 4-year period (accurate classification = 87.5%). Learning across multiple trials may provide the most sensitive index for initial diagnosis of MCI, but inclusion of additional variables may enhance overall accuracy and may represent the optimal strategy for identifying individuals most likely to progress to dementia.     

镇静与镇痛在ICU机械通气患者中的应用变化

探讨ICU内机械通气患者应用镇痛剂、镇静剂及肌松剂的情况及其对机械通气和预后的影响。回顾性分析我院中心ICU2006年、2007年收治的244例行有创机械通气治疗超过48h患者的临床资料,并将患者分为2006年组和2007年纽,用统计软件分析患者在年龄、性别、入ICU时APACHEⅡ评分、血糖、血浆白蛋白、基础疾病,气管插管时间、机械通气时间、ICU住院天数、镇痛与镇静剂应用的时间、机械通气时是否使用肌松剂、Ramsay评分及病死率方面是否存在差别。统计分析显示2006年组和2007年组在年龄、性剐、入ICU时APACHEⅡ评分、血糖、血浆白蛋白、是否使用肌松剂及基础疾病方面无差别;与2006年组相比2007年组患者气管插管时间、机械通气时间及ICU住院天数均缩短,镇痛与镇静剂应用时间均缩短,Ramsay评分降低,病死率下降。提示对机械通气的危重症患者应合理使用镇痛剂与镇静剂。     

Sex differences in semantic language processing: a functional MRI study

Predictions based on two models of sex differences in cerebral organization of language were compared by examining fMRI patterns of 10 females and 9 males during a semantic processing task. Both groups displayed activation of left inferior frontal gyrus (IFG), left superior temporal gyrus (STG), and cingulate. Females, but not males, showed bilateral IFG and STG activation. Further analyses revealed females had less diffuse left activation and greater right posterior temporal and insula region activation than males. Results support both an interhemispheric and an intrahemispheric model of sex differences in language, suggesting that the models may not be mutually exclusive.     

王岱舆的“天命有三品”论与儒家的天命观

王岱舆作为明末清初四教（儒、释、道、回）皆通的伊斯兰著名学者,他提出的“天命有三品”论,既适应了当时以儒家为主流文化的背景,也保持了其独特的伊斯兰性,在巧妙地处理与儒家天命观分歧的同时,又开放地拿儒家文化为己所用,从而为两种文明都赢得了宽松的环境,使得两种文明能够共存、共荣、共同发展。本文从王岱舆天命观与儒家天命观的介绍入手,分析其与儒家天命观的契合与分歧。