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871.
Five experiments demonstrate that negative identity priming is contingent on stimulus repetition. In ignored repetition conditions, priming was initially positive and became negative as the number of repetitions increased. Moreover, it was repetition as a target, not as a distractor, that was critical for negative priming. The effects of repetition were general: They were found with both naming and same-different paradigms, verbal and pictorial material, familiar and unfamiliar stimuli, and vocal and manual responses. Findings support an activation-based model of negative priming (G. B. Malley & D. L. Strayer, 1995) and are problematic for the episodic retrieval model of negative priming (W. T. Neill & L. A. Valdes, 1992). Finally, the experiments did not replicate B. DeSchepper and A. Treisman's (1996) reported negative priming with nonrepeated novel shapes.  相似文献   
872.
It has been suggested that neural systems for lexical processing of nouns and verbs are anatomically distinct. The aim of the present study was to investigate if brain asymmetry for the processing of these two grammatical classes is also different. Neurologically intact adults performed a lateralized lexical decision task with grammatically unambiguous words of high, medium, and low degrees of imagery. For error scores a right visual field (RVF) advantage and an overall effect of imageability were obtained. For latency scores grammatical class and imageability modified visual field differences: in the noun class a RVF advantage was obtained only for low imagery nouns, while for the verbs the RVF advantage was present for both medium and low imagery verbs. These results suggest that the participation of right hemisphere neural systems in the processing of verbs is more limited than in the processing of nouns.  相似文献   
873.
874.
The authors examined the manner in which self-selected movement frequencies are impacted upon by repeated engagement in an intralimb coordination task and by alterations in the inertial characteristics of the limb. Twelve healthy adult volunteers rhythmically flexed and extended their elbow and wrist joints at a comfortable self-established frequency in 1 of 2 modes of coordination (in-phase and antiphase), while grasping 1 of 3 weighted dowels (no-weight condition [0.03 kg], light weight condition [0.5 kg], heavy weight condition [1.0 kg]). The movement frequencies adopted by subjects on the 3rd of 3 weekly sessions, following more than 120 experimental trials, were appreciably higher than those obtained during an initial session. The addition of mass to the system had an inconsistent influence upon the preferred frequency of movement. When subjects' limbs were loaded with what was deemed to be a light weight (0.5 kg), the movement frequencies that were adopted were indistinguishable from those selected when there was no (0.03 kg) loading of the limbs. In contrast, when subjects' limbs were loaded with a relatively heavy weight (1 kg), the resulting self-selected movement frequencies were reliably lower than when there was no loading of the limbs. The adopted frequency of movement was also influenced in a reliable fashion by the mode of coordination in which the movements were prepared. Those results are discussed with reference to mechanical and neuromuscular constraints on coordination dynamics.  相似文献   
875.
In 3 experiments, the authors examined movement space-time variability as a function of the force-time properties of the initial impulse in a movement timing task. In the range of motion and movement time task conditions, peak force, initial rate of force, and force duration were manipulated either independently or in combination across a range of parameter values. The findings showed that (a) impulse variability is predicted well by the elaboration of the isometric force variability scaling functions of L. G. Carlton, K. H. Kim, Y. T. Liu, and K. M. Newell (1993) to movement, and (b) the movement spatial and temporal outcome variability are complementary and well predicted by an equation treating the variance of force and time in Newton's 2nd law as independent random variables. Collectively, the findings suggest that movement outcome variability is the product of a coherent space-time function that is driven by the nonlinear scaling of the force-time properties of the initial impulse.  相似文献   
876.
本实验旨在探索儿童对抽象图画情绪寓意敏感性的发展规律以及文化因素的影响。被试年龄跨度从 5岁至高中学生。根据被试利用形态、主题、情绪等图片特性作为识辨依据的特点来发现规律。儿童对抽象图画寓意敏感性的发展与表征水平相关。年幼儿童只能利用颜色或图形等单一信息维量进行判断 ,年长儿童及中学生可以综合利用形态、主题、情绪等多个维量判断。在寓意明确的图片识辨中 ,儿童对积极寓意的识辨成绩较优。在双关寓意的图片识辨中 ,儿童组倾向于选择具有积极寓意的线索 ,而中学生组会受到识辨经验的影响。文化与教育方式影响儿童对抽象图画情绪寓意的理解。中国幼教方式有助于儿童对图画认知与情绪成分的识辨。  相似文献   
877.
The role of memory in the Tower of London task   总被引:5,自引:0,他引:5  
The Tower of London (TOL) task is widely used as a neuropsychological test of planning. Relatively little is known of the cognitive components of the task, and in particular the role of memory in performance. The current studies on normal adults looked at the role of verbal and spatial working memory in the TOL. The effects of verbal and visuospatial dual-task manipulations on TOL performance were examined in an experiment with 36 participants. Both verbal and visuospatial executive secondary tasks caused poorer performance on the TOL; however, concurrent articulatory suppression enhanced performance. The results suggest that executive and spatial components are important in the task, and raise questions about the role of preplanning in the TOL.  相似文献   
878.
Numerous studies have shown that sex differences in visuospatial tasks vary in size and direction depending on the nature of the task, with large differences favoring males on tasks that require transformations in visuospatial working memory. The cognitive processes underlying these differences were investigated using laboratory tasks developed by Dror and Kosslyn (1994). Four cognitive components of visuospatial working memory were assessed—image generation, maintenance, scanning, and transformation—in an attempt to identify the components that would show differential effects for females and males. The image generation task required retrieval of shape information from long-term memory, generation of a visual image in working memory, and utilization of the information about the shape in a decision task. The image maintenance task required only the latter two processes. The information processing demands required by scanning and rotation tasks came from the need to transform the visual image so that it could be used in decision making. Males responded more quickly on all four tasks (ds between .63 and .77), with no between-sex differences in accuracy. We concluded that speed of processing is central to understanding sex differences in visuospatial working memory. We discuss implications of these findings for performance on real-world visuospatial tasks.  相似文献   
879.
In this article, we will first present an overview of the epidemiology and classification of headaches, distinguishing between primary headaches (in which the headache itself is the primary disorder) and secondary headaches (ie, headaches due to an underlying condition, such as a neoplastic and/or space-occupying lesion, a cerebrovascular accident, or other type of structural brain lesion). We will use the current classification system of the International Headache Society, focusing on primary headache disorders (migraine, tension-type headache, cluster headache), which we will discuss from the practical clinical perspectives of diagnosis and clinical management. Throughout this article, we will emphasize the chronicity and periodicity of headaches as a type of chronic pain syndrome.  相似文献   
880.
Conduct Disorder in Girls: A Review of the Literature   总被引:8,自引:0,他引:8  
The study of Conduct Disorder (CD) has primarily been limited to boys. The lack of research resulted from a premise that CD in girls was rare. However, CD in girls is a relatively common psychiatric diagnosis, and appears to be associated with several serious outcomes, such as Antisocial Personality Disorder and early pregnancy. Understanding gender differences in the course and severity of CD may lead to important information about etiology. Empirical studies on precursors, developmental course, risk factors and treatment for CD in girls are reviewed, while highlighting similarities and differences between girls and boys. Generally, CD symptoms in girls are stable. Precursors to CD in girls probably include Oppositional Defiant Disorder and temperamental factors, but also may include certain negative cognitions. What distinguishes CD in girls is the high risk they have to develop comorbid conditions, especially internalizing disorders. Risk factors for CD in girls partly overlap with those known for boys, but some factors appear to be highly salient for girls. Finally, there may be some significant effects of gender on treatment efficacy. Implications of these findings for future etiologic research are discussed.  相似文献   
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