Syntactic violations in sentences elicit a P600 component in the event-related potential, which is frequently interpreted as signaling reanalysis or repair of the sentence structure. However, P600 components have been reported also for semantic and combined semantic and syntactic violations, giving rise to still other interpretations. In many of these studies, the violation might be of special significance for the task of the participants; however there is a lack of studies directly targeting task effects on the P600. Here we repeated a previously published study but using a probe verification task, focusing on individual words rather than on sentence correctness and directly compared the results with the previous ones. Although a (somewhat smaller) N400 component occurred also in the present study, we did not observe a parietal P600 component. Instead, we found a late anterior negativity. Possibly, the parietal P600 observed in sentence acceptability paradigms relates to the target value of the violations or to late sentence structure-specific processes that are more task-sensitive than the N400 and which are or not initiated in the probe verification task. In any case the present findings show a strong dependency of P600-eliciting processes from attention to the sentences context whereas the N400 eliciting processes appear relatively robust.
We investigated the motor planning and reprogramming of facial expressions of happiness and anger with a response-priming task. A response signal commanded the production of a validly or invalidly cued facial expression. Electromyogram showed performance costs of inhibiting the falsely prepared expression and reprogramming the correct one in invalid trials. These performance costs were larger in zygomaticus major than corrugator supercilii, indicating better control over the latter. Event-related potentials indicated no emotion specificity in the initial preparation of anger and happiness in the contingent negative variation. During reprogramming, anger came along with greater allocation of processing resources for the inhibition of the preactivated motor plan (N2), and the updating of a new one (P3). These additional processing resources and the faster control over corrugator may reflect the need for being quick and accurate in displaying threat.
Background and Purpose Adjuvant whole-breast irradiation after breast-conserving surgery, typically delivered over several weeks, is the traditional standard of care for low-risk breast cancer. More recently, hypofractionated, partial-breast irradiation has increasingly become established. Neoadjuvant single-fraction radiotherapy (rt) is an uncommon approach wherein the unresected lesion is irradiated preoperatively in a single fraction. We developed the signal (Stereotactic Image-Guided Neoadjuvant Ablative Radiation Then Lumpectomy) trial, a prospective single-arm trial to test our hypothesis that, for low-risk carcinoma of the breast, the preoperative single-fraction approach would be feasible and safe.Methods Patients presenting with early-stage (T < 3 cm), estrogen-positive, clinically node-negative invasive carcinoma of the breast with tumours at least 2 cm away from skin and chest wall were enrolled. All patients received prone breast magnetic resonance imaging (mri) and prone computed tomography simulation. Treatable patients received a single 21 Gy fraction of external-beam rt (as volumetric-modulated arc therapy) to the primary lesion in the breast, followed by definitive surgery 1 week later. The primary endpoints at 3 weeks, 6 months, and 1 year were toxicity and cosmesis (that is, safety) and feasibility (defined as the proportion of mri-appropriate patients receiving rt).Results Of 52 patients accrued, 27 were successfully treated. The initial dosimetric constraints resulted in a feasibility failure, because only 57% of eligible patients were successfully treated. Revised dosimetric constraints were developed, after which 100% of patients meeting mri criteria were treated according to protocol. At 3 weeks, 6 months, and 1 year after the operation, toxicity, patient- and physician-rated cosmesis, and quality of life were not significantly different from baseline.Conclusions The signal trial presents a feasible method of implementing single-dose preoperative rt in earlystage breast cancer. This pilot study did not identify any significant toxicity and demonstrated excellent cosmetic and quality-of-life outcomes. Future randomized multi-arm studies are required to corroborate these findings.
3D left ventricle (LV) segmentation on echocardiography is very important for diagnosis and treatment of cardiac disease. It is not only because of that echocardiography is a real-time imaging technology and widespread in clinical application, but also because of that LV segmentation on 3D echocardiography can provide more full volume information of heart than LV segmentation on 2D echocardiography. However, 3D LV segmentation on echocardiography is still an open and challenging task owing to the lower contrast, higher noise and data dimensionality, limited annotation of 3D echocardiography. In this paper, we proposed a novel real-time framework, i.e., VoxelAtlasGAN, for 3D LV segmentation on 3D echocardiography. This framework has three contributions: 1) It is based on voxel-to-voxel conditional generative adversarial nets (cGAN). For the first time, cGAN is used for 3D LV segmentation on echocardiography. And cGAN advantageously fuses substantial 3D spatial context information from 3D echocardiography by self-learning structured loss; 2) For the first time, it embeds the atlas into an end-to-end optimization framework, which uses 3D LV atlas as a powerful prior knowledge to improve the inference speed, address the lower contrast and the limited annotation problems of 3D echocardiography; 3) It combines traditional discrimination loss and the new proposed consistent constraint, which further improves the generalization of the proposed framework. Voxe-lAtlasGAN was validated on 60 subjects on 3D echocardiography and it achieved satisfactory segmentation results and high inference speed. The mean surface distance is 1.85 mm, the mean hausdorff surface distance is 7.26 mm, mean dice is 0.953, the correlation of EF is 0.918, and the mean inference speed is 0.1s. These results have demonstrated that our proposed method has great potential for clinical application.
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