女性不同时期高血压的临床特征与治疗原则

女性因在不同时期内分泌的变化使其血压变化规律与男性有异,本文阐述了女性不同时期血压的临床特征和治疗原则;妊娠前及妊娠期慢性高血压的治疗及降压药物的选择;妊娠高血压综合征的处理原则及授乳期安全哺乳方法。     

Chronic violent video game exposure and desensitization to violence: Behavioral and event-related brain potential data

Numerous studies have shown that exposure to media violence increases aggression, though the mechanisms of this effect have remained elusive. One theory posits that repeated exposure to media violence desensitizes viewers to real world violence, increasing aggression by blunting aversive reactions to violence and removing normal inhibitions against aggression. Theoretically, violence desensitization should be reflected in the amplitude of the P300 component of the event-related brain potential (ERP), which has been associated with activation of the aversive motivational system. In the current study, violent images elicited reduced P300 amplitudes among violent, as compared to nonviolent video game players. Additionally, this reduced brain response predicted increased aggressive behavior in a later task. Moreover, these effects held after controlling for individual differences in trait aggressiveness. These data are the first to link media violence exposure and aggressive behavior to brain processes hypothetically associated with desensitization.     

An improved learning algorithm for random neural networks based on particle swarm optimization and input-to-output sensitivity

Extreme learning machine (ELM) for random single-hidden-layer feedforward neural networks (RSLFN) has been widely applied in many fields in the past ten years because of its fast learning speed and good generalization performance. But because traditional ELM randomly selects the input weights and hidden biases, it typically requires high number of hidden neurons and thus decreases its convergence performance. It is necessary to select optimal input weights and hidden biases to improve the convergence performance of the traditional ELM. Generally, the single-hidden-layer feedforward neural networks (SLFN) with low input-to-output sensitivity will cause good robustness of the network, which may further lead into good generalization performance. Moreover, particle swarm optimization (PSO) has no complicated evolutionary operators and fewer parameters need to adjust, and is easy to implement. In this study, an improved ELM based on PSO and input-to-output sensitivity information is proposed to improve RSLFN’s convergence performance. In the improved ELM, PSO encoding the input to output sensitivity information of the SLFN is used to optimize the input weights and hidden biases. The improved ELM could obtain better generalization performance as well as improve the conditioning of the SLFN by decreasing the input-to-output sensitivity of the network. Finally, experiment results on the regression and classification problems verify the improved performance the proposed ELM.     

Bi-hemispheric anodal transcranial direct current stimulation worsens taekwondo-related performance

Transcranial Direct Current Stimulation (tDCS) is a neuromodulatory technique that has been used as an ergogenic aid in exercise/sports performance. However, little is known about its effects on highly-trained subjects, as athletes. The present study aimed to verify the effects of bi-hemispheric anodal tDCS (a-tDCS) on the performance of taekwondo athletes. Additionally, we investigated the persistence of the effects of the a-tDCS one hour after it. Nineteen Taekwondo athletes received active or sham bi-hemispheric a-tDCS over the primary motor cortex (M1). a-tDCS was delivered at 1.5 mA for 15 min. Athletes performed Countermovement Jumps (CMJ) and the Frequency Speed of Kick Test (FSKT) immediately (Mo1) and one hour after stimulation (Mo2). The athletes also reported their session-rating of perceived exertion (session-RPE). The total number of kicks (TK) was higher in sham than in the active a-tDCS condition (p < 0.01). In addition, TK was higher at Mo2 than at Mo1 (p < 0.05). Similarly, the session-RPE was higher in the a-tDCS condition (p < 0.05) and was greater one-hour post-stimulation (p < 0.01). No differences were found for CMJ performance (p > 0.05). Thus, bi-hemispheric a-tDCS worsens performance of taekwondo athletes, and the effect remains present even 1 h after the stimulation.     

Emergent complexity: What uphill analysis or downhill invention cannot do

In these notes we review emergent phenomena in complex systems, emphasizing ways to identify potential underlying universal mechanisms that generate complexity. The discussion focuses on the emergence of collective behavior in dynamical systems when they are poised near a critical point of a phase transition, either by tuning or by self-organization. We then present the rationale for our proposal that the brain is naturally poised near criticality and review recent results as well as the implications of this view of the functioning brain.     

Autism Overflows: Increasing Prevalence and Proliferating Theories

This selective review examines the lack of an explanation for the sharply increasing prevalence of autism, and the lack of any synthesis of the proliferating theories of autism. The most controversial and most widely disseminated notion for increasing prevalence is the measles–mumps–rubella/thimerosal vaccine theory. Less controversial causes that have been proposed include changes in autism diagnostic criteria, increasing services for autism, and growing awareness of the disorder. Regardless of its causes, the increasing prevalence of autism has put pressure on the field of autism research to generate productive and predictive theories of autism. However, the heterogeneity of brain deficits, impaired behaviors, and genetic variants in autism have challenged researchers and theorists, and despite 45 years of research, no standard causal synthesis has emerged. Research going forward should assume that autism is an aggregation of myriad independent disorders of impaired sociality, social cognition, communication, and motor and cognitive skills.     

Evidence that blatant versus subtle stereotype threat cues impact performance through dual processes

An experiment tested three competing hypotheses for how blatant and subtle stereotype threat cues influence the performance of female sports participants on a golf-putting task. A “predominant” model predicts that blatant threat cues have a more negative effect on performance than subtle threat cues, whereas an “additive” model predicts that both cues combine to have a greater negative effect than either threat cue alone. However, a “dual process” model predicts that each threat cue has an independent negative influence through separate mechanisms. To test these predictions, we varied the presence of blatant (e.g., the task frame) and subtle cues (e.g., the gender of the experimenter) for negative stereotypes about female athletes, and then measured both the number of strokes required to finish the course and accuracy on the last putt of each hole. The results supported the dual process model prediction: females required more strokes to finish the golf task when it was framed as measuring gender differences compared to racial differences in athletic ability, and females performed less accurately on the last putt of each hole in the presence of a male versus a female experimenter. The discussion focuses on how the presence of multiple stereotype threat cues can induce independent mechanisms that may have separate but simultaneously deleterious effects on performance.     

Comparison of chemosensory, auditory and visual event-related potential amplitudes

To enhance understanding of neuropsychological processing underlying chemosensory event-related potentials (CSERPs), the objective of the present study was to compare CSERPs with auditory (AERPs) and visual event-related potentials (VERPs), and to approach the question of similarities in neuropsychological processing by means of correlation and cluster analyses. A multisensory ERP protocol was used, in which olfactory/chemosomatosensory (pyridine), auditory (1000-Hz tone) and visual (white circle) stimuli were presented in a pseudo-randomized sequence to 18 young, healthy adults. The results show (1) a morphological relation between P2 and P3 components that is different for the chemosensory than for the auditory and visual modalities, (2) a relatively weak association between the chemosensory and auditory/visual modalities for P3 in terms of both correlation and cluster, and (3) a P2/P3 cluster for the chemosensory but not auditory or visual modality. This supports the claim that the chemosensory P2 and P3 components reflect similar neuropsychological processes.     

The thalamus and basal ganglia: What is exactly where?: A reply to ‘Neuropsychological consequences of right thalamic injury: Case study and review,’ MJ Summers, Brain and Cognition 50 (2002)

The present paper re-analyzes anatomical and clinical data of a previous case report ([Summers, 2002]). In this case study, a patient with severe neuropsychological and behavioral impairments is described and it is claimed that these impairments are causally linked to an right thalamic lesion. A simple method how to perform a lesion analysis is introduced which shows that PD’s lesion was a striatocapsular hematoma, and not a thalamic bleeding. The results of this anatomical re-analysis challenge the original behavioral-lesion hypothesis and emphasize the importance to provide appropriate data on brain lesions and clinical findings in neuropsychological case reports.     

A comparison of body size ideals, body dissatisfaction, and media influence between female track athletes, martial artists, and non-athletes

ObjectivesIn assessments of body image among athletes, there remains an important discrepancy between studies reporting, on one hand, increased body dissatisfaction among athletes and, on the other, lower body image concerns. In order to help resolve this contradiction, the present study examined body size ideals, body dissatisfaction, and media influence among female recreational athletes and non-athletes.MethodForty-one track athletes (a judged sport in which leanness is actively promoted), 47 women involved in Taek Won Do (a martial art with little or no emphasis on leanness), and 44 non-athletes completed self-report measures of ideal body size, body dissatisfaction, and media influence, and provided their demographic details.ResultsResults showed that, after controlling for participants' body mass index (BMI), there were no significant between-group differences in ideal body size. By contrast, track athletes reported the highest body dissatisfaction scores and the highest internalisation of athletic media messages. Results of a regression analysis showed that, for the total sample, participants' BMI and internalisation of athletic media messages predicted body dissatisfaction over-and-above involvement in the different sports.ConclusionThese results support the suggestion that women participating in leanness-promoting sports experience greater body dissatisfaction than women in other sports or non-athletes.