Orientation specificity of learning vernier discriminations
Orientation selective neurons in the primary visual cortex typically respond to a range of orientations that covers 20, or more, while in psychophysical experiments, orientation bandwidth is often clearly narrower. Here, we measure the orientation specificity of perceptual learning for vernier discriminations. More than 70 observers, in separate groups, practiced a vernier discrimination task with a constant stimulus orientation. After a 1 h session of training, the vernier was rotated by 2 degrees, 4 degrees, 10 degrees, 20 degrees, 45 degrees or 90 degrees. Improvement through training in the first session transferred to the second session (tested on the next day) up to 10 degrees of stimulus rotation. We found no transfer for rotations of 20 degrees, 45 degrees and 90 degrees Hence, the orientation half-bandwidth of perceptual learning is around 150, leading to a bandwidth of 30 degrees and corresponding to that of single neurons in early visual cortices, while being narrower than that in higher cortical areas. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords: Early vision ; Spatial filters ; Human psychophysics ; Complex cells ; Orientation bandwidth ; Hyperacuity ; Vernier acuity ; Inferior Temporal Neurons ; Spatial-Frequency ; Perceptual Performance ; Texture-Discrimination ; Macaque Monkey ; Visual-Cortex ; Human Vision ; Selectivity ; Plasticity ; Hyperacuity
Record created on 2010-04-30, modified on 2016-08-08