NtMYB1 and NtNCED1/2 control abscisic acid biosynthesis and tepal senescence in Chinese narcissus (Narcissus tazetta).

Chinese narcissus (Narcissus tazetta var. chinensis cv. 'Jinzhanyintai') is one of the 10 most famous traditional flowers of China, having a beautiful and highly ornamental flower with a rich fragrance. However, the flower longevity affects its commercial appeal. While petal senescence in Narcissus is ethylene-independent and abscisic acid-dependent, the regulatory mechanism has yet to be determined. In this study, we identified a R2R3-MYB gene (NtMYB1) from Narcissus tazetta and generated oeNtMYB1 and Ntmyb1 RNA interference mutants in Narcissus as well as an oeNtMYB1 construct in Arabidopsis. Overexpressing NtMYB1 in Narcissus or Arabidopsis led to premature leaf yellowing, an elevated level of total carotenoid, a reduced level of chlorophyll b, and a decrease in photosystem II fluorescence (Fv/Fm). A dual-luciferase assay and chromatin immunoprecipitation-quantitative PCR revealed that NtMYB1 directly binds to the promoter of NtNCED1 or NtNCED2 and activates NtNCED1/2 gene expression both in vitro and in vivo. Moreover, overexpressing NtMYB1 accelerated abscisic acid biosynthesis, up-regulated the content of zeatin and abscisic acid, and down-regulated the level of ß-carotene and gibberellin A1, leading to petal senescence and leaf yellowing in Narcissus. This study revealed a regulatory process that is fundamentally different between non-photosynthetic organs and leaves.

Altered cortical gyrification, sulcal depth, and fractal dimension in the autism spectrum disorder comorbid attention-deficit/hyperactivity disorder than the autism spectrum disorder.

Autism spectrum disorder (ASD) frequently occurs accompanied by attention-deficit/hyperactivity disorder (ADHD), which catches increasing attention. The comorbid diagnosis of ASD with ADHD (ASD + ADHD) is permitted in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). However, compared to autism spectrum disorder without other symptoms (ASD-only), the special neural underpinnings in ASD+ADHD remain unclear. Therefore, this study aimed to uncover the differences in cortical complexity between ASD + ADHD and ASD-only patients. A total of 114 ASD participants (i.e. containing 40 ASD + ADHD and 74 ASD-only participants) with T1-weighted magnetic resonance images were collected from the Autism Brain Imaging Data Exchange II. Afterward, a surface-based morphometry method was carried out to compare the cortical complexity (i.e. gyrification index, fractal dimension, and sulcal depth) between the ASD + ADHD and ASD-only cohorts. Results showed the increased fractal dimension in the right fusiform gyrus of the ASD + ADHD cohort in comparison to the ASD-only cohort. Moreover, the ASD + ADHD cohort exhibited increased sulcal depth in the left middle temporal gyrus/inferior temporal gyrus and right middle temporal gyrus compared to the ASD-only cohort. Last but not least, the increased gyrification index in the insula/postcentral gyrus was observed in the ASD + ADHD cohort in comparison to the ASD-only cohort. Overall, the present study contributes to the delineation of particular structural abnormalities in ASD + ADHD than ASD-only, enriching the evidence of the combined phenotype of ASD + ADHD.

Altered Brain Connectivity Patterns of Individual Differences in Insightful Problem Solving.

Insightful problem solving (IPS) attracts widespread attention in creative thinking domains. However, the neural underpinnings of individual differences in IPS are still unclear. The purpose of this research was to investigate inherent full-brain connectivity patterns at voxel-level in IPS. Sixty-two healthy participants were enrolled in the study. We used a voxelwise full-brain network measurement, degree centrality (DC), to depict the characteristics of cerebral network involved in individual differences in IPS. For each participant, we employed a chunk decomposition paradigm, using Mandarin characters as stimuli, to estimate the individual differences in IPS. Results showed that DC in the inferior frontal gyrus, and the middle frontal gyrus/precentral gyrus positively correlated with IPS, while the anterior cingulate cortex, and the brainstern/cerebellum/thalamus exhibited negative correlations with IPS. Using each cluster above as a seed, we performed seed-based functional connectivity analysis further. Results showed that IPS was mainly involved in the default mode network, containing the key regions of precuneus and medial prefrontal cortex. All in all, this research may shed new lights on understanding the neural underpinnings of individual differences in IPS.

Brain Structural Correlates of Dispositional Insight and the Mediation Role of Neuroticism in Young Adults.

Studies on the neural correlates of episodic insight have made significant progress in the past decades. However, the neural mechanisms underlying dispositional insight are largely unknown. In the present study, we recruited forty-four young, healthy adults and performed several analyses to reveal the neural mechanisms of dispositional insight. Firstly, a voxel-based morphometry (VBM) technique was used to explore the structural brain mechanisms of dispositional insight. We found that dispositional insight was significantly and negatively correlated with the regional gray matter volume (rGMV) in the left thalamus (TLM.L), right temporoparietal junction (TPJ.R), and left dorsal medial prefrontal cortex (DMPFC.L). Secondly, we performed a seed-based resting-state functional connectivity (RSFC) analysis to complement the findings of VBM analysis further. The brain regions of TLM.L, DMPFC.L, and TPJ.R were selected as seed regions. We found that dispositional insight was associated with altered RSFC between the DMPFC.L and bilateral TPJ, between the TPJ.R and left dorsolateral prefrontal cortex, left ventrolateral prefrontal cortex, DMPFC.L, TPJ.L, right insula, and right cerebellum. Finally, a mediation analysis found that the personality of neuroticism partially mediated the relationship between the brain region of TLM.L and dispositional insight. These findings imply that dispositional insight has a specific functional and structural neural mechanism. The personality of neuroticism may play a pivotal role in the processes of dispositional insight.

Common and specific neural correlates underlying insight and ordinary problem solving.

Previous studies have investigated the cognitive and neural mechanisms underlying insight problem solving (INPS). However, it is still unclear which mechanisms are common to both INPS and ordinary problem solving (ORPS), and which are distinctly involved in only one of these processes. In this study, we selected two types of Chinese character chunk decompositions, ordinary Chinese character chunk decomposition (OCD) and creative Chinese character chunk decomposition (CCD), as representatives of ORPS and INPS, respectively. By using functional magnetic resonance imaging (fMRI) to record brain activations when subjects executed OCD or CCD operations, we found that both ORPS and INPS resulted in significant activations in the widespread frontoparietal cognitive control network, including the middle frontal gyrus, inferior frontal gyrus, and inferior parietal lobe. Furthermore, compared with ORPS, INPS led to greater activations in higher-level brain regions related to symbolic processing in the default mode network, including the anterior cingulate cortex, superior temporal gyrus, angular gyrus, and precuneus. Conversely, ORPS induced greater activations than INPS in more posterior brain regions related to visuospatial attention and visual perception, such as the inferior temporal gyrus, hippocampus, and middle occipital gyrus/superior parietal gyrus/fusiform gyrus. In addition, an ROI analysis corroborated the neural commonalities and differences between ORPS and INPS. These findings provide new evidence that ORPS and INPS rely on common as well as distinct cognitive processes and cortical mechanisms.

Interhemispheric functional connectivity and its relationships with creative problem solving.

Creative problem solving (CPS) is a particular mental process when people solve problems. Findings from previous research, which used functional MRI, showed that CPS could involve specific neural mechanisms. However, few studies have directly explored the changes of interhemispheric resting-state functional connectivity during CPS. Recently, a validated voxel-mirrored homotopic connectivity (VMHC) method has been widely used to calculate the interhemispheric resting-state functional connectivity. In this study, we recruited 60 participants and used a revised chunk decomposing task to estimate participants' individual differences during CPS. Then, the VMHC method was used to explore neural correlates underlying individual differences of CPS. Results showed that altered VMHC in the bilateral middle frontal gyrus/precentral gyrus, bilateral hippocampus/insula/amygdala, and bilateral fusiform gyrus/cerebellum/middle occipital gyrus was related to individual differences of CPS. These brain regions reflect the information integration of both hemispheres might be critical for CPS. Therefore, our results may shed light on the neural correlates of CPS.

Correction: Neural correlates of creative insight: Amplitude of low-frequency fluctuation of resting-state brain activity predicts creative insight.

[This corrects the article DOI: 10.1371/journal.pone.0203071.].

Neural correlates of creative insight: Amplitude of low-frequency fluctuation of resting-state brain activity predicts creative insight.

Creative insight has attracted much attention across cultures. Although previous studies have explored the neural correlates of creative insight by functional magnetic resonance imaging (fMRI), little is known about intrinsic resting-state brain activity associated with creative insight. In the present study, we used amplitude of low-frequency fluctuation (ALFF) as an index in resting-state fMRI (rs-fMRI) to identify brain regions involved in individual differences in creative insight, which was measured by the response time of creative Chinese character chunk decomposition. Our results showed that ALFF in the superior frontal gyrus (SFG) positively predicted creative insight, while ALFF in the middle cingulate cortex/insula cortex (MCC/IC), superior temporal gyrus/angular gyrus (STG/AG), anterior cingulate cortex/caudate nucleus (ACC/CN), and culmen/declive (CU/DC) negatively predicted creative insight. Moreover, these findings indicate that spontaneous brain activity in multiple regions related to breaking mental sets, solutions exploring, evaluation of novel solutions, forming task-related associations, and emotion experience contributes to creative insight. In conclusion, the present study provides new evidence to further understand the cognitive processing and neural correlates of creative insight.