Age-related Changes in Postural Sway During Sit-to-stand in Typical Children and Children with Cerebral Palsy

Objective: To assess age-related changes in postural sway during sit-to-stand (STS) in typical children (TC) and children with mild cerebral palsy (CP). Methods: Thirty-five TC and 23 children with mild CP were allocated in four different age groups: 5–6, 7–9, 10–12, and 13–15 years; they all performed STS movements over a force plate. Anterior-posterior and medial-lateral amplitude of center of pressure (CoP) displacement, area and velocity of CoP sway were analyzed and compared between the age groups for TC and children with CP. Results: TC at 5 to 6 years of age showed higher values of anterior-posterior CoP displacement and Area of CoP sway than at 10–12 years, during the stabilization phase. There were no age-related changes for CP. Conclusion: TC change their postural sway during the last STS phase over the years, reducing their body sway. Children with CP did not show age-related changes in sway during STS, reflecting a distinct rhythm of postural control development in this population.     

Contributions of the dorsal hippocampus and the dorsal subiculum to processing of idiothetic information and spatial memory

It is well established that the dorsal hippocampal formation is crucial for spatial memory in rats. However, little is known about the distinct functions of the dorsal hippocampus and the dorsal subiculum. To examine the role of the dorsal hippocampus and the dorsal subiculum, Long-Evans rats with excitotoxic lesions (NMDA) of the dorsal hippocampus (DH), the dorsal subiculum (DS), or both (DHDS), and controls were trained on a nonmatching-to-place task. Then, to identify the strategy used by each group, they were tested on the same task in the dark with the T-maze being rotated between the sample and the test runs. In the light, rats with combined lesions were impaired. In the dark, groups DH, DS, and controls performed near chance level except in trials without rotation, suggesting the use of a sense of direction. The same rats were trained on a radial-arm maze task. In the light, where proximal visual cues were accessible, combined lesions affected performance whereas in the dark, it was impaired by all lesions. This experiment demonstrated that the dorsal subiculum and the dorsal hippocampus play a crucial role in processing idiothetic information and/or in maintenance of this information in memory.     

Lateralized cognition: asymmetrical and complementary strategies of pigeons during discrimination of the "human concept"

This study was aimed at revealing which cognitive processes are lateralized in visual categorizations of "humans" by pigeons. To this end, pigeons were trained to categorize pictures of humans and then tested binocularly or monocularly (left or right eye) on the learned categorization and for transfer to novel exemplars (Experiment 1). Subsequent tests examined whether they relied on memorized features or on a conceptual strategy, using stimuli composed of new combinations of familiar and novel humans and backgrounds (Experiment 2), whether the hemispheres processed global or local information, using pictures with different levels of scrambling (Experiment 3), and whether they attended to configuration, using distorted human figures (Experiment 4). The results suggest that the left hemisphere employs a category strategy and concentrates on local features, while the right hemisphere uses an exemplar strategy and relies on configuration. These cognitive dichotomies of the cerebral hemispheres are largely shared by humans, suggesting that lateralized cognitive systems already defined the neural architecture of the common ancestor of birds and mammals.     

Are there differential word length effects in the two visual fields?

This study examined whether differential word length effects in the two visual fields imply hemisphere-dependent modes of word recognition. Length was defined as the number of constituent characters of Chinese foreign names (Experiments 1 and 2), as the number of constituent morphemes of three-character words (Experiments 3 and 4), and as that of constituent words of phrases (Experiments 5 and 6). Two types of experimental tasks were adopted, one required linguistic judgments on overall items (Experiments 1, 3, and 5) and the other was target detection tasks performed on the same set of stimuli (Experiments 2, 4, and 6). Five of the six experiments failed to find any kind of interaction between length and visual field. An interaction was observed only for the detection of characters embedded in foreign names, that is, when lexical access is least involved in the task, suggesting that word recognition plays a minimum role in the phenomenon. Other observations suggested that modes of word recognition are more frequency-dependent than hemisphere-dependent, and that Chinese compound words and phrases, although hardly distinguishable, do behave differently.     

The bilingual Loch Ness Monster raises its non-asymmetric head again-or, why bother with such cumbersome notions as validity and reliability? Comments on Evans et al. (2000)

All of the experimental studies of the past 25 years combined and the meta-analyses of their findings have not advanced our knowledge of the lateralization of language in bilingual speakers one bit. We are left with a clutter of inherently uninterpretable contradictory results. Successive studies do not contribute a single brick to the edifice or a single piece to the puzzle-only more confusion. study is no exception. So far, there has been no demonstration of the validity of any experimental paradigm claiming to measure degree of language laterality in bilingual speakers. Experimentation is pointless unless the nature of what is alleged to be lateralized is clearly defined and the validity of the measures employed has been established. Because of the lack of validity of the paradigms used in bilingual laterality studies, experiments and meta-analyses of their findings cannot have any scientific significance. Like their predecessors, Evans et al. pay lip service to a number of methodological problems, but ignore their implications and simply carry on anyway. The authors ought to demonstrate, rather than assume, that degree of visual half-field advantage for single words corresponds to degree of lateralization of any component of language (even if only of words).     

Perseverative Thinking and Health: Neurovisceral Concomitants

In the present paper we present the outlines of a model that may help to guide us in our understanding of the relationship between perseverative thinking and health. We will emphasize the relationship between perseverative thinking and vagal cardiac control and propose a group of underlying neural structures that serve to integrate these functions in the service of self-regulation and adaptability of the organism. We will attempt to place this network in the context of systems models which involve feedback and feedforward circuits with special attention to negative feedback mechanisms and inhibitory processes. From a systems perspective, inhibitory processes can be viewed as negative feedback circuits that allow for the interruption of ongoing behavior and the re-deployment of resources to other tasks. When these negative feedback mechanisms are compromised, positive feedback loops may develop as a result of dis-inhibition. From this perspective, the relative sympathetic activation seen in perseverative thinking may represent dis-inhibition due to faulty inhibitory mechanisms.     

高频超声对膝关节病变的观察

通过超声对髌上囊、股骨髁间软骨情况、胭窝滑囊、髌腱等膝部结构的观察,评价超声对膝关节病变的辅助诊断、观察疗效的价值。通过高频超声对膝关节肿胀、疼痛病例纽与对照组、病例组治疗前后髌上囊液体、滑膜、股骨髁间软骨、胭窝滑囊积液情况以及髌腱厚度及回声进行对比观察。病例组髌上囊液体及滑膜增厚,股骨髁间软骨多有不同程度改变,胭窝滑...     

A brief review on the use of functional near-infrared spectroscopy (fNIRS) for language imaging studies in human newborns and adults

Upon stimulation, real time maps of cortical hemodynamic responses can be obtained by non-invasive functional near-infrared spectroscopy (fNIRS) which measures changes in oxygenated and deoxygenated hemoglobin after positioning multiple sources and detectors over the human scalp. The current commercially available transportable fNIRS systems have a time resolution of 1-10 Hz, a depth sensitivity of about 1.5 cm, and a spatial resolution of about 1 cm. The goal of this brief review is to report infants, children and adults fNIRS language studies. Since 1998, 60 studies have been published on cortical activation in the brain’s classic language areas in children/adults as well as newborns using fNIRS instrumentations of different complexity. In addition, the basic principles of fNIRS including features, strengths, advantages, and limitations are summarized in terms that can be understood even by non specialists. Future prospects of fNIRS in the field of language processing imaging are highlighted.     

Interspecific aggressiveness and reactivity in mouse-killing and nonkilling rats: Compared effects of olfactory bulb removal and raphe lesions

The experiments aimed at uncovering possible correlations between inter-specific aggressiveness and general and emotional responsiveness (appraised by means of the open-field technique) in the rat. Killer rats showed a higher level of emotional responsiveness than nonkillers. Removal of the olfactory bulbs induced an increased reactivity both in the rats which were converted into killers in those whose behavior toward mice remained unchanged. Destruction of the dorsal and medial nuclei of the raphé induced a clear hyperreactivity in most lesioned animals, but provoked initiation of mouse-killing behavior in only one-third. When produced in rats which had remained nonkillers following olfactory bulb removal, the raphé lesion clearly enhanced both the general and the emotional responsiveness; it provoked initiation of mouse-killing behavior in about 75% of the lesioned animals. The discussion bears on the correlations between interspecific aggressiveness and experimentally induced hyperreactivity in the rat.     

The temporally-integrated causality landscape: A theoretical framework for consciousness and meaning

Theoretical approaches to understanding consciousness have begun to converge upon areas of general agreement, yet substantive differences remain. Here, I introduce a new theoretical framework for the emergence of consciousness from the functional integration of the thalamocortical system: the Temporally-Integrated Causality Landscape (TICL). TICL presents a novel perspective which addresses important phenomenological characteristics of consciousness that other frameworks, such as IIT, do not. First, the TICL is based upon the observation that conscious experiences are temporally continuous, not discrete. Secondly, the TICL establishes a thalamocortical basis for the point-of-view. According to TICL, consciousness is composed of contents that arise from neuronal subsystems that have meaning from the point-of-view of the larger, integrated system in which they are nested. Meaningful contents emerge from the subsystems because they exhibit a level of temporally-integrated causality (TIC) that is distinguishable from that of the larger system.