Parametric effects of syntactic-semantic conflict in Broca's area during sentence processing

The hypothesized role of Broca’s area in sentence processing ranges from domain-general executive function to domain-specific computation that is specific to certain syntactic structures. We examined this issue by manipulating syntactic structure and conflict between syntactic and semantic cues in a sentence processing task. Functional neuroimaging revealed that activation within several Broca’s area regions of interest reflected the parametric variation in syntactic-semantic conflict. These results suggest that Broca’s area supports sentence processing by mediating between multiple incompatible constraints on sentence interpretation, consistent with this area’s well-known role in conflict resolution in other linguistic and non-linguistic tasks.     

Speech presentation cues moderate frontal EEG asymmetry in socially withdrawn young adults

Socially withdrawn individuals display solitary behavior across wide contexts with both unfamiliar and familiar peers. This tendency to withdraw may be driven by either past or anticipated negative social encounters. In addition, socially withdrawn individuals often exhibit right frontal electroencephalogram (EEG) asymmetry at baseline and when under stress. In the current study we examined shifts in frontal EEG activity in young adults (N=41) at baseline, as they viewed either an anxiety-provoking or a benign speech video, and as they subsequently prepared for their own speech. Results indicated that right frontal EEG activity increased, relative to the left, only for socially withdrawn participants exposed to the anxious video. These results suggest that contextual affective cues may prime an individual's response to stress, particularly if they illustrate or substantiate an anticipated negative event.     

Sensitivity to lateral information on a perceptual word identification task in French third and fifth graders

This study aimed at examining sensitivity to lateral linguistic and nonlinguistic information in third and fifth grade readers. A word identification task with a threshold was used, and targets were displayed foveally with or without distractors. Sensitivity to lateral information was inferred from the deterioration of the rate of correct word identification when displayed with distractors. Results show that the two reader groups were sensitive to both right and left lateral information. The area of sensitivity to this information was more extended for the identification of easy words than difficult words. Examination of the detrimental effect of distractors suggests that in both third and fifth graders, the impact of lateral information on foveal processing is the result of a general distraction effect, but also of linguistic processing whose nature remains to be clarified.     

Role of frontal cortex in attentional capture by singleton distractors

The role of frontal cortex in selective attention to visual distractors was examined in an attentional capture task in which participants searched for a unique shape in the presence or absence of an additional colour singleton distractor. The presence of the additional singleton was associated with slower behavioural responses to the shape target, and a greater neural signal in inferior frontal gyrus. To investigate the involvement of cognitive control functions of the frontal lobes in the capture of attention by the additional singletons, we measured the effect of the additional singleton in a context of either low or high working memory load. Whereas behavioural capture was unaffected by the level of load on working memory, greater activity associated with the presence of the additional singleton was observed in inferior frontal gyrus, but only under high load. This effect was greater in participants who experienced greater capture. We argue that the role of inferior frontal gyrus in selective attention is to detect potential sources of distraction.     

Menstrual cycle-related changes of functional cerebral asymmetries in fine motor coordination

Fluctuating sex hormone levels during the menstrual cycle have been shown to affect functional cerebral asymmetries in cognitive domains. These effects seem to result from the neuromodulatory properties of sex hormones and their metabolites on interhemispheric processing. The present study was carried out to investigate whether functional cerebral asymmetries in fine motor coordination as reflected by manual asymmetries are also susceptible to natural sex hormonal variations during the menstrual cycle. Sixteen right-handed women with a regular menstrual cycle performed a finger tapping paradigm consisting of two conditions (simple, sequential) during the low hormone menstrual phase and the high estrogen and progesterone luteal phase. To validate the luteal phase, saliva levels of free progesterone (P) were analysed using chemiluminescence assays. As expected, normally cycling women showed a substantial decrease in manual asymmetries in a more demanding sequential tapping condition involving four fingers compared with simple (repetitive) finger tapping. This reduction in the degree of dominant (right) hand manual asymmetries was evident during the luteal phase. During the menstrual phase, however, manual asymmetries were even reversed in direction, indicating a slight advantage in favour of the non-dominant (left) hand. These findings suggest that functional cerebral asymmetries in fine motor coordination are affected by sex hormonal changes during the menstrual cycle, probably via hormonal modulations of interhemispheric interaction.     

Reducing self‐control depletion effects through enhanced sensitivity to implementation: Evidence from fMRI and behavioral studies

Research suggests self-control relies on a limited set of resources that can be diminished by use. Recent theories posit that there are two stages of self-control: recognizing the need for control and implementing controlled responses. We conducted a functional magnetic resonance imaging experiment and an intervention experiment to investigate whether one or both stages were affected by the prior exercise of self-control. Results from both experiments indicated that only the implementation stage was affected. Further, we demonstrate that self-control can be increased by an intervention designed to boost implementation, as opposed to the recognition of the need to control one's responses.     

Inhibitory Control in Children with Frontal Infarcts Related to Sickle Cell Disease

Evidence from past studies indicates that children with traumatic brain injury experience difficulties with inhibitory control. Less is known about inhibitory control in children with frontal brain injury related to cerebral infarction. We compared the inhibitory performance of children with frontal infarcts related to sickle cell disease with that of a control group of children with sickle cell disease but no history of cerebral infarction. On a stimulus-response reversal task, children with frontal infarcts made significantly more accuracy errors in the inhibitory condition than controls. Findings from this study and from previous research suggest that impairments in inhibitory control are common following frontal injury in a range of pediatric populations.     

卫生经济学视野中的医患合谋

从分析医患合谋道德风险的影响因素入手,结合卫生经济学的供给曲线和需求曲线探讨产生医患合谋道德风险的原因和规避策略.发现医疗保险的供给方(保险机构)、医疗服务的提供方(医疗服务机构)和医疗保险的被保险方(医疗保险的消费者,即接受医疗服务的消费者或患者)三者之间信息不对称是导致道德风险的重要因素,保险基金风险更多是来自医疗服务提供方的道德风险.建议从建立信息公开制度,加强监督;加强激励,遏制道德风险;运用技术,规范行为三方面规范医疗服务提供方的行为.     

Biomechanical Study of Tandem Stance in Healthy Young Adults: Effects of Weight-Bearing and Limb Dominance

Postural strategies of healthy young adults to control tandem stance were investigated through the calculation of the relative contribution of the two loading-unloading (LU) and pressure-distribution (PD) mechanisms and the two legs for controlling the resultant center-of-pressure (CP_Res) displacements. Weight-bearing asymmetry and limb dominance were also studied. For antero-posterior and medio-lateral CP_Res displacements, LU and PD mechanisms mainly contribute, respectively. A significant LU contribution is nonetheless observed for medio-lateral control, due to a lateral gap between the CP positions under each foot despite a strict sagittal alignment for the two feet. Moreover, for medio-lateral control, the respective involvement of the two legs is related to the level of weight-bearing asymmetry, whereas the front leg mainly controls the antero-posterior sway. By specifying potential effects of body-weight asymmetry and limb dominance, to a better testing of patients with deficiencies in lateral sway control.     

Pure agraphia in Romaji after left inferior frontal gyrus infarction: A case of selective deficit in syllable-to-grapheme conversion in Japanese

The Japanese writing system employs two distinct categories of characters: Kana and Kanji. The difference between Kana and Kanji writing corresponds roughly to that between phonological and lexical systems in Western languages. When typing, most Japanese use alphabetical characters based purely on phonological rules. In particular, the Romaji system is used, in which a syllable consists of a single vowel, a consonant–vowel compound (e.g., ka, ki), or a sequence of consonant–y(semivowel)–vowel (e.g., kya, kyu). We describe a right-handed Japanese patient who developed pure agraphia that affected Romaji writing but preserved Kana and Kanji writing and who had a lesion in the left pars opercularis of the inferior frontal gyrus that extended to the anterior precentral gyrus. The patient demonstrated literal paragraphia in spelling Romaji across modalities. Our findings suggested that the patient’s agraphia in Romaji after a confined left frontal infarction was manifested by a selective impairment in syllable-to-grapheme conversion.