Prolonged exposure to an oriented line shifts the perceived orientation of a subsequently observed line in the opposite direction, a phenomenon known as the tilt aftereffect (TAE). Here we consider whether the TAE for line stimuli is mediated by a mechanism that integrates the local parts of the line into a single global entity prior to the site of adaptation, or the result of the sum of local ...

Neurons in visual cortex are selective for the orientation of a visual stimulus, while the receptive fields of their thalamic input are circular. Cortical orientation selectivity arises from the organization of both thalamic input and local cortical circuits. In this issue of Neuron, Schummers and colleagues provide evidence that the local circuit mechanisms contributing to orientation selectiv...

The aim of this paper is to present a study where we evaluate the optimal inclusion of the texture orientation in the classification process. In this paper the orientation for each pixel in the image is extracted using the partial derivatives of the Gaussian function and the main focus of our work is centred on the evaluation of the local dominant orientation (which is calculated by combining t...

IRON is a low level operator dedicated to the estimation of single and multiple local orientations in images. Previous works have shown that IRON is more accurate and more selective than Gabor and Steerable filters, for textures corrupted with Gaussian noise. In this paper, we propose two new features. The first one is dedicated to the estimation of orientation in images damaged by impulsive no...

In order to investigate the processes which integrate local orientation information in observers with strabismic amblyopia, we measured contrast thresholds for discriminating the global orientation of a pattern (3 "bars") comprised of Gabor patches. We found that in both eyes of amblyopic observers, as has been reported for normal observers [Saarinen, Levi & Shen (1997) Proceedings of the Natio...