Neuroelectromagnetic correlates of perceptual closure processes

Perceptual closure refers to the coherent perception of an object under circumstances when the visual information is incomplete. Although the perceptual closure index observed in electroencephalography reflects that an object has been recognized, the full spatiotemporal dynamics of cortical source activity underlying perceptual closure processing remain unknown so far. To address this question, we recorded magnetoencephalographic activity in 15 subjects (11 females) during a visual closure task and performed beamforming over a sequence of successive short time windows to localize high-frequency gamma-band activity (60–100 Hz). Two-tone images of human faces (Mooney faces) were used to examine perceptual closure. Event-related fields exhibited a magnetic closure index between 250 and 325 ms. Time-frequency analyses revealed sustained high-frequency gamma-band activity associated with the processing of Mooney stimuli; closure-related gamma-band activity was observed between 200 and 300 ms over occipitotemporal channels. Time-resolved source reconstruction revealed an early (0–200 ms) coactivation of caudal inferior temporal gyrus (cITG) and regions in posterior parietal cortex (PPC). At the time of perceptual closure (200–400 ms), the activation in cITG extended to the fusiform gyrus, if a face was perceived. Our data provide the first electrophysiological evidence that perceptual closure for Mooney faces starts with an interaction between areas related to processing of three-dimensional structure from shading cues (cITG) and areas associated with the activation of long-term memory templates (PPC). Later, at the moment of perceptual closure, inferior temporal cortex areas specialized for the perceived object are activated, i.e., the fusiform gyrus related to face processing for Mooney stimuli.

Overjet correction and space closure mechanisms for Class II treatment by extracting the maxillary first molars

To analyze the mechanism of overjet correction and space closure when treating Class II Division 1 patients by extracting the maxillary first molars.

Patent foramen ovale closure in recreational divers: effect on decompression illness and ischaemic brain lesions during long-term follow-up

To test the effect of patent foramen ovale (PFO) closure on neurological events in divers.

Long-term propensity score-matched comparison of percutaneous closure of patent foramen ovale with medical treatment after paradoxical embolism

Patients with ischemic stroke or transient ischemic attack presumably related to patent foramen ovale (PFO) are at risk for recurrent cerebrovascular events. Differences in long-term clinical outcome were investigated among patients with percutaneous PFO closure and those who received medical treatment.

Early closure of ileostomy is associated with less postoperative nausea and vomiting

Background/Aims: Temporary loop ileostomy is increasingly used in colorectal surgery but necessitates secondary closure. We evaluated postoperative complications, particularly nausea and vomiting, in patients with early, intermediate, or late elective ileostomy closure. Methods: We included all patients undergoing ileostomy closure from 2001 to 2008. Time from ileostomy construction to closure was classified as early (EC, <12 weeks), intermediate (IC, 12–18 weeks), and late (LC, >18 weeks). Using multivariable logistic regression, we compared the frequency of postoperative complications between the groups. Results: We included 134 patients (87 males; median age 71 years, range 29–91). Carcinoma of the rectum (n = 67, 50%) was the main reason for ileostomy construction. The median time to ileostomy closure was 103 days (range 8–461). Among patients with EC, IC, and LC, postoperative nausea occurred in 50.0, 73.1, and 78.6%, respectively (p = 0.006), and postoperative vomiting in 22.5, 57.7, and 59.5%, respectively (p = 0.001). Adjusting for important covariates, the odds ratio for postoperative nausea was 2.0 (95% CI 0.76–5.1) for IC and 4.1 (95% CI 1.2–14.3) for LC compared to EC (p = 0.069). For postoperative vomiting, adjusted odds ratios were 3.8 (95% CI 1.4–10.4) for IC and 4.6 (95% CI 1.4–15.5) for LC (p = 0.012). Other complications did not differ between the groups. Conclusions: These findings suggest that early ileostomy closure might reduce postoperative nausea and vomiting.