For the past 150 years, neurobiological models of language have debated the role of key brain regions in language function. One consistently debated set of issues concern the role of the left inferior frontal gyrus in syntactic processing. Here we combine measures of functional activity, grey matter integrity and performance in patients with left hemisphere damage and healthy participants to ask whether the left inferior frontal gyrus is essential for syntactic processing. In a functional neuroimaging study, participants listened to spoken sentences that either contained a syntactically ambiguous or matched unambiguous phrase. Behavioural data on three tests of syntactic processing were subsequently collected. In controls, syntactic processing co-activated left hemisphere Brodmann areas 45/47 and posterior middle temporal gyrus. Activity in a left parietal cluster was sensitive to working memory demands in both patients and controls. Exploiting the variability in lesion location and performance in the patients, voxel-based correlational analyses showed that tissue integrity and neural activity—primarily in left Brodmann area 45 and posterior middle temporal gyrus—were correlated with preserved syntactic performance, but unlike the controls, patients were insensitive to syntactic preferences, reflecting their syntactic deficit. These results argue for the essential contribution of the left inferior frontal gyrus in syntactic analysis and highlight the functional relationship between left Brodmann area 45 and the left posterior middle temporal gyrus, suggesting that when this relationship breaks down, through damage to either region or to the connections between them, syntactic processing is impaired. On this view, the left inferior frontal gyrus may not itself be specialized for syntactic processing, but plays an essential role in the neural network that carries out syntactic computations.

Background With increases in inactive lifestyles and mounting pressure for academic excellence in Chinese younger populations, lack of physical activity and increased prevalence of obesity have become a major public health concern in China. The purpose of this study is to provide updated estimates on the prevalence of meeting moderate-vigorous physical activity (MVPA) and screen viewing time guidelines, and overweight and obesity among Chinese school-aged children and adolescents, with a secondary aim examining variations in prevalence by sex, grade groupings, and residential location. Methods The study sample came from the 2017 Physical Activity and Fitness in China—The Youth Study, a cross-sectional and national survey of 131,859 students (aged 7 to 19 years) from 986 public schools in China. Measures of MVPA, screen viewing time, and age- and sex-specific overweight and obese body mass index were used to calculate national prevalence estimates of Chinese school-aged children and adolescents. Results In 2017, 34.1% (95% confidence interval [CI], 34.09–34.11%) of children and adolescents met MVPA guidelines and 65.4% (95% CI, 65.39–65.41%) adhered to screen viewing time guidelines. The prevalence of overweight and obesity was 15.1% (95% CI, 15.09–15.11%) and 10.7% (95% CI, 10.69–10.71%), respectively. Prevalence estimates differed by sex (boys, girls), grade grouping (primary schools, junior middle schools, junior high schools), and residential location (rural, urban). Conclusions There remains a low prevalence of meeting MVPA guidelines and high prevalence of overweight and obesity in Chinese school-aged children and adolescents. Future efforts should focus on monitoring the trend of these behavioral and health risk factors to inform school policies and programs aimed at increasing physical activity and reducing and preventing obesity in younger populations in China. Electronic supplementary material The online version of this article (10.1186/s12889-019-6515-9) contains supplementary material, which is available to authorized users.

Highlights This study provides the prevalence estimates of physical activity, sedentary behavior, and sleep duration (isolation and combination) in a nationally representative sample ( n = 114,072) of Chinese children and adolescents of grades 4–12. Only about 5% of Chinese children and adolescents show the most ideal combination of 24-h movement behaviors. Chinese children and adolescents with younger ages, higher parental education levels, and higher family incomes exhibit favorable 24-h movement behaviors. Chinese children and adolescents with the most ideal 24-h movement behaviors have lower risks of overweight and obesity, especially in children of grades 4–6 and girls of grades 7–9.

Abstract■ Recognizing an object involves more than just visual analyses; its meaning must also be decoded. Extensive research has shown that processing the visual properties of objects relies on a hierarchically organized stream in ventral occipitotemporal cortex, with increasingly more complex visual features being coded from posterior to anterior sites culminating in the perirhinal cortex (PRC) in the anteromedial temporal lobe (aMTL). The neurobiological principles of the conceptual analysis of objects remain more controversial. Much research has focused on two neural regions-the fusiform gyrus and aMTL, both of which show semantic category differences, but of different types. fMRI studies show category differentiation in the fusiform gyrus, based on clusters of semantically similar objects, whereas category-specific deficits, specifically for living things, are associated with damage to the aMTL. These category-specific deficits for living things have been attributed to problems in differentiating between highly similar objects, a process that involves the PRC. To determine whether the PRC and the fusiform gyri contribute to different aspects of an objectʼs meaning, with differentiation between confusable objects in the PRC and categorization based on object similarity in the fusiform, we carried out an fMRI study of object processing based on a featurebased model that characterizes the degree of semantic similarity and difference between objects and object categories. Participants saw 388 objects for which feature statistic information was available and named the objects at the basic level while undergoing fMRI scanning. After controlling for the effects of visual information, we found that feature statistics that capture similarity between objects formed category clusters in fusiform gyri, such that objects with many shared features (typical of living things) were associated with activity in the lateral fusiform gyri whereas objects with fewer shared features (typical of nonliving things) were associated with activity in the medial fusiform gyri. Significantly, a feature statistic reflecting differentiation between highly similar objects, enabling object-specific representations, was associated with bilateral PRC activity. These results confirm that the statistical characteristics of conceptual object features are coded in the ventral stream, supporting a conceptual feature-based hierarchy, and integrating disparate findings of category responses in fusiform gyri and category deficits in aMTL into a unifying neurocognitive framework. ■

The findings warn of the insufficiency of PA and the excess of SB in Chinese city children and youth.