冠状动脉病变范围与心率变异性的相关性研究

本研究通过对69例CHD患者（完成冠状动脉造影）进行Gensini评分、分组,同时设正常对照组56例。全部进行24h动态心电图监测,并做时域指标和频域指标的HRV分析。结果显示CHD组HRV各项指标均低于对照组（P〈0．05）,不同冠状动脉病变范围和程度其时域指标及频域指标降低程度不同,各组对照具有显著性差异（P〈0．...     

Contribution of the parafascicular nucleus in the spontaneous object recognition task

The parafascicular (PF) nucleus, a posterior component of the intralaminar nuclei of the thalamus, is considered to be an essential structure in the feedback systems of basal ganglia–thalamo-cortical circuits critically involved in cognitive processes. The specific role played by multimodal information encoded in PF neurons in learning and memory processes is still unclear. We conducted two experiments to investigate the role of the PF in the spontaneous object recognition (SOR) task. The behavioral effects of pretraining rats with bilateral lesions of PF with N-methyl-D-aspartate (NMDA) were compared to vehicle controls. In the first experiment, rats were tested on their ability to remember the association immediately after training trials and in the second experiment after a 24 h delay. Our findings provide evidence that PF lesions critically affect both SOR tests and support its role in that non-spatial form of relational memory.     

Gender characteristics of cerebral hemodynamics during complex cognitive functioning

Functional Transcranial Doppler sonography (fTCD) has been applied to assess peak mean cerebral blood flow velocity (MFV) with a high temporal resolution during cognitive activation. Yet, little attention has been devoted to gender-related alterations of MFV, including spectral analysis. In healthy subjects, fTCD was used to investigate a series of cerebral hemodynamic parameters in the middle cerebral arteries (MCA) during the Trail Making Tests (TMT), a means of selective attention and complex cognitive functioning. In females, there was a frequency peak at 0.375 Hz in both MCA, and we observed a dynamic shift in hemispheric dominance during that condition. Further, after the start phase, there was an MFV decline during complex functioning for the entire sample. These novel results suggest condition-specific features of cerebral hemodynamics in females, and it adds to the notion that gender is a fundamental confounder of brain physiology.     

Gradual increase of perturbation load induces a longer retention of locomotor adaptation in children with cerebral palsy

The goal of this study is to determine whether the size and the variability of error have an impact on the retention of locomotor adaptation in children with cerebral palsy (CP). Eleven children with CP, aged 7–16 years old, were recruited to participate in this study. Three types of force perturbations (i.e., abrupt, gradual and noisy loads) were applied to the right leg above the ankle starting from late stance to mid-swing in three test sessions while the subject walked on a treadmill. Spatial-temporal gait parameters were recorded using a custom designed 3D position sensor during treadmill walking. We observed that children with CP adapted to the resistance force perturbation and showed an aftereffect consisting of increased step length after load release. Further, we observed a longer retention of the aftereffect for the condition with a gradual load than that with an abrupt load. Results from this study suggested that the size of error might have an impact on the retention of motor adaptation in children with CP with a longer retention of motor adaptation for the condition with a small size of error than that with a large error. In addition, enhanced variability of error seems facilitate motor learning during treadmill training. Results from this study may be used for the development of force perturbation based training paradigms for improving walking function in children with CP.     

Hemispheric asymmetries in the split-fovea model of semantic processing

We report a series of neural network models of semantic processing of single English words in the left and the right hemispheres of the brain. We implement the foveal splitting of the visual field and assess the influence of this splitting on a mapping from orthography to semantic representations in single word reading. The models were trained on English four-letter words, presented according to their frequency in all positions encountered during normal reading. The architecture of the model interacted with the training set to produce processing asymmetries comparable to those found in behavioral studies. First, the cueing effects of dominant and subordinate meanings of ambiguous words were different for words presented to the left or to the right of the input layer. Second, priming effects of groups of related words were stronger in the left input than the right input of the model. These effects were caused by coarser-coding in the right half compared with the left half of the model, an emergent effect of the split model interacting with informational asymmetries in the left and right parts of words in the lexicon of English. Some or all of the behavioral data for reading single words in English may have a similar origin.     

Bimanual circle drawing in children with spastic hemiparesis: effect of coupling modes on the performance of the impaired and unimpaired arms

The present study examined the effect of interlimb coupling on the performance of the impaired and unimpaired arm in children with spastic hemiparesis during bimanual circle drawing. The following questions were addressed: (1) does coupling positively influence the performance of the impaired arm compared to single-hand performance and (2) is such an effect dependent on mode of coordination (i.e., symmetric versus asymmetric). Twelve children with spastic hemiparesis produced circle drawings on a digitizer under different task conditions. Spatiotemporal characteristics and quality of movement of pen trajectories of the individual limbs as well as interlimb relative phase were analysed. Coupling in a symmetric coordination mode resulted in a decrease of temporal variability and an increase of smoothness of circle drawing movements in the impaired arm compared to single-handed performance. Coupling in an asymmetric coordination mode resulted in an increase of spatial and temporal variability in the unimpaired arm. It is concluded that coupling may enhance the performance of the impaired arm in children with spastic hemiparesis, but only during symmetric bimanual coordination. A possible underlying neural mechanism that might explain these findings is discussed.     

From cybernetics to brain theory,and more: A memoir

While structured as an autobiography, this memoir exemplifies ways in which classic contributions to cybernetics (e.g., by Wiener, McCulloch & Pitts, and von Neumann) have fed into a diversity of current research areas, including the mathematical theory of systems and computation, artificial intelligence and robotics, computational neuroscience, linguistics, and cognitive science. The challenges of brain theory receive special emphasis. Action-oriented perception and schema theory complement neural network modeling in analyzing cerebral cortex, cerebellum, hippocampus, and basal ganglia. Comparative studies of frog, rat, monkey, ape and human not only deepen insights into the human brain but also ground an EvoDevoSocio view of “how the brain got language.” The rapprochement between neuroscience and architecture provides a recent challenge. The essay also assesses some of the social and theological implications of this broad perspective.     

Effects of some physiological and pharmacological manipulations on shock- facilitated mouse killing by onychomys leucogaster (Northern grasshopper mouse)

Onychomys leucogaster (northern grasshopper mice) were induced to kill mice with response-contingent shock, and the effects of several physiological, pharmacological, and endocrinological variables were assessed. Lesions of the septum facilitated mouse killing, while lesions of the amygdala abolished spontaneous mouse killing and delayed shock-facilitated killing. Chlorpromazine (2.5–5 mg/kg) and chlordiazepoxide (5–10 mg/kg) facilitated mouse killing on postdrug trials but did not affect killing when the animals were drugged. Adrenalectomy, castration, and castration adrenalectomy did not alter the frequency of kill nor were sex-related differences in killing noted. These results were compared to those found by others studying the effects of lesions and drugs on mouse killing by rats.     

Colateralization of Broca's area and the visual word form area in left-handers: fMRI evidence

Language production has been found to be lateralized in the left hemisphere (LH) for 95% of right-handed people and about 75% of left-handers. The prevalence of atypical right hemispheric (RH) or bilateral lateralization for reading and colateralization of production with word reading laterality has never been tested in a large sample. In this study, we scanned 57 left-handers who had previously been identified as being clearly left (N = 30), bilateral (N = 7) or clearly right (N = 20) dominant for speech on the basis of fMRI activity in the inferior frontal gyrus (pars opercularis/pars triangularis) during a silent word generation task. They were asked to perform a lexical decision task, in which words were contrasted against checkerboards, to test the lateralization of reading in the ventral occipitotemporal region. Lateralization indices for both tasks correlated significantly (r = 0.59). The majority of subjects showed most activity during lexical decision in the hemisphere that was identified as their word production dominant hemisphere. However, more than half of the sample (N = 31) had bilateral activity for the lexical decision task without a clear dominant role for either the LH or RH, and three showed a crossed frontotemporal lateralization pattern. These findings have consequences for neurobiological models relating phonological and orthographic processes, and for lateralization measurements for clinical purposes.