We explore the influence of categories on perception through one such phenomenon, the perceptual magnet effect, selleck inhibitor in which discriminability between vowels is reduced near prototypical vowel sounds. We present a Bayesian model to explain why this reduced discriminability might occur: It arises as a consequence of optimally solving the statistical

problem of perception in noise. In the optimal solution to this problem, listeners’ perception is biased toward phonetic category means because they use knowledge of these categories to guide their inferences about speakers’ target productions. Simulations show that model predictions closely correspond to previously published human data, and novel experimental results provide evidence for the predicted link between perceptual warping and noise. The model unifies several previous accounts of the perceptual magnet effect and provides a framework for exploring categorical effects in other domains.”
“Background: Atherosclerotic occlusive disease of the proximal vertebral artery is an important cause of cerebrovascular ischemic events with a significant associated morbidity and mortality. Endovascular treatment has emerged as a promising tool of the therapeutic armamentarium, MK-8776 concentration along with medical therapy and surgical reconstruction. Our objective was to systemically review the pertinent evidence on the endovascular

management of proximal vertebral artery disease and perform an analysis of the published outcomes.

Methods: A systematic review of the literature identified all studies reporting percutaneous transluminal angioplasty or stenting, or both, for proximal vertebral artery stenosis. Web-based search engines were searched using the Medical Subject Headings terms “”vertebral artery,”" “”angioplasty,”" and “”stents”" in all possible science combinations. Studies comprising a series of at least five patients were considered for analysis. Periprocedural transient ischemic attack and stroke and death from any cause <= 30 days of treatment were defined as the primary outcome end points.

Results:

One randomized controlled trial comparing angioplasty and stenting of the proximal vertebral artery and medical therapy was identified. No comparative studies of endovascular treatment and open surgical repair were found. Forty-two selected studies reported endovascular treatment (angioplasty or stenting, or both) of 1117 vertebral arteries in 1099 patients. The weighted mean technical success rate was 97% (range, 36%-100%). Periprocedural transient ischemic attack occurred in 17 patients (1.5%). The combined stroke and death rate was 1.1%. Recurrent symptoms of vertebrobasilar insufficiency developed in 65 of 967 patients (8%) within a reported follow-up of 6 to 54 months. Restenosis developed in 183 of 789 patients (23%) who underwent follow-up imaging (range, 0%-58%).