Ho Cindy S, Giaschi Deborah E
Department of Psychology, University of British Columbia, Canada.
Vision Res. 2006 Dec;46(28):4595-603. doi: 10.1016/j.visres.2006.09.025. Epub 2006 Nov 13.
Direction discrimination thresholds for maximum motion displacement (Dmax) are not fixed, but are stimulus dependent. Dmax increases with reduced dot probability or increased dot size. We previously reported abnormal Dmax in the fellow eyes of amblyopic children for dense patterns of small dots. To determine how deficits of Dmax in amblyopic eyes compare to those in fellow eyes, thresholds were obtained in both eyes of 9 children with unilateral amblyopia and 9 control children. The expected increase in Dmax was observed for reduced dot probability and increased dot size conditions relative to baseline in both control and amblyopic groups. Both eyes of the amblyopic group demonstrated significant deficits. Our findings implicate abnormal binocular motion processing, which may involve both low-level and high-level motion mechanisms, in the neural deficit underlying amblyopia.
最大运动位移（Dmax）的方向辨别阈值并非固定不变，而是依赖于刺激。Dmax会随着点概率降低或点大小增加而增大。我们之前报道过，对于密集的小点点阵，弱视儿童对侧眼的Dmax异常。为了确定弱视眼的Dmax缺陷与对侧眼的缺陷相比情况如何，我们对9名单侧弱视儿童和9名对照儿童的双眼进行了阈值测量。在对照和弱视组中，相对于基线，在点概率降低和点大小增加的情况下，均观察到了Dmax的预期增加。弱视组的双眼均表现出明显缺陷。我们的研究结果表明，弱视潜在的神经缺陷涉及异常的双眼运动处理，这可能涉及低级和高级运动机制。
