Damage to the adult, primary visual cortex (V1) causes severe visual impairment that was previously thought to be permanent, yet several visual pathways survive V1 damage, mediating residual, often unconscious functions known as "blindsight." Because some of these pathways normally mediate complex visual motion perception, we asked whether specific training in the blind field could improve not just simple but also complex visual motion discriminations in humans with long-standing V1 damage. Global direction discrimination training was administered to the blind field of five adults with unilateral cortical blindness. Training returned direction integration thresholds to normal at the trained locations. Although retinotopically localized to trained locations, training effects transferred to multiple stimulus and task conditions, improving the detection of luminance increments, contrast sensitivity for drifting gratings, and the extraction of motion signal from noise. Thus, perceptual relearning of complex visual motion processing is possible without an intact V1 but only when specific training is administered in the blind field. These findings indicate a much greater capacity for adult visual plasticity after V1 damage than previously thought. Most likely, basic mechanisms of visual learning must operate quite effectively in extrastriate visual cortex, providing new hope and direction for the development of principled rehabilitation strategies to treat visual deficits resulting from permanent visual cortical damage.
Taken together with emerging results in both visual and other auditory areas, these findings suggest that neurons whose responses reflect complex interactions between stimulus position and eye position set the stage for the eventual convergence of auditory and visual information.
Parastomal hernia is one of the most common complications following stoma creation and its prevalence is only expected to increase. It often leads to a decrease in the quality of life for patients due to discomfort, pain, frequent ostomy appliance leakage, or peristomal skin irritation and can result in significantly increased healthcare costs. Surgical technique for parastomal hernia repair has evolved significantly over the past two decades with the introduction of new types of mesh and laparoscopic procedures. The use of prophylactic mesh in high-risk patients at the time of stoma creation has gained attention in lieu of several promising studies that have emerged in the recent days. This review will attempt to demonstrate the burden that parastomal hernias present to patients, surgeons, and the healthcare system and also provide an overview of the current management and surgical techniques at both preventing and treating parastomal hernias. i 2014 S. Karger AG, Basel
Visceral obesity, history of inguinal hernia, and location of specimen extraction site are significantly associated with the development of an incisional hernia, whereas BMI is poorly associated with hernia development. These findings suggest that a lateral transverse location is the incision site of choice and that new strategies, such as prophylactic mesh placement, should be considered in viscerally obese patients.
Laparoscopic adhesiolysis requires a specific skill set and may not be appropriate in all patients. Notwithstanding this, the laparoscopic approach demonstrates a benefit in 30-day morbidity and mortality even after controlling for preoperative patient characteristics. Given these findings in more than 9,000 patients and consistent rates of SBO requiring surgical intervention in the United States, increasing the use of laparoscopy could be a feasible way of to decrease costs and improving outcomes in this population.
Abstract& We investigated the format of the code for sound location in the inferior colliculi of three awake monkeys (Macaca mulatta). We found that roughly half of our sample of 99 neurons was sensitive to the free-field locations of broadband noise presented in the frontal hemisphere. Such neurons nearly always responded monotonically as a function of sound azimuth, with stronger responses for more contralateral sound locations. Few, if any, neurons had circumscribed receptive fields. Spatial sensitivity was broad: the proportion of the total sample of neurons responding to a sound at a given location ranged from 30% for ipsilateral locations to 80% for contralateral locations. These findings suggest that sound azimuth is represented via a population rate code of very broadly responsive neurons in primate inferior colliculi. This representation differs in format from the place code used for encoding the locations of visual and tactile stimuli and poses problems for the eventual convergence of auditory and visual or somatosensory signals. Accordingly, models for converting this representation into a place code are discussed. &
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