Spang K, Grimsen C, Herzog M H, Fahle M
Department of Human Neurobiology, Bremen University, Germany.
Vision Res. 2010 Feb 22;50(4):479-85. doi: 10.1016/j.visres.2009.12.008. Epub 2009 Dec 23.
Orientation selective neurons in the primary visual cortex typically respond to a range of orientations that covers 20 degrees 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 1h 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 15 degrees, 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.
初级视觉皮层中的方向选择性神经元通常对20度或更大范围的一系列方向做出反应，而在心理物理学实验中，方向带宽往往明显更窄。在这里，我们测量了对游标辨别进行知觉学习的方向特异性。70多名观察者分成不同组，在恒定刺激方向下练习游标辨别任务。经过1小时的训练后，将游标旋转2度·、4度、10度、20度、45度或90度。在第一次训练中通过训练取得的进步会转移到第二次训练（第二天进行测试），刺激旋转角度可达10度。我们发现20度、45度和90度的旋转没有转移效果。因此，知觉学习的方向半带宽约为15度，导致带宽为30度，这与早期视觉皮层中单个神经元的带宽相对应，同时比更高皮层区域的带宽更窄。
