Department of Psychology, University of South Carolina, 1512 Pendleton Street, Columbia, SC 29208, United States.
Res Dev Disabil. 2011 May-Jun;32(3):1021-9. doi: 10.1016/j.ridd.2011.01.038. Epub 2011 Feb 21.
Williams Syndrome (WS) is a developmental disorder typified by deficits in visuospatial cognition. To understand the nature of this deficit, we characterized how people with WS perceive visual orientation, a fundamental ability related to object identification. We compared WS participants to typically developing children (3-6 years of age) and typical adults in an orientation discrimination task with four stimulus types (small circular, large circular, collinear elongated and parallel elongated gratings). We measured orientation discrimination thresholds and the proportion of orthogonal errors (i.e., mirror-image reversal errors). We evaluated how these metrics (1) are modulated by stimulus condition, and (2) vary with chronological or mental age. We found that orientation perception in WS is comparable to that of typically developing children. Orientation discrimination thresholds were better for elongated gratings than circular gratings across all participant groups. For large circular gratings, the proportion of orthogonal errors was disproportionately greater in WS participants and typically developing 3-6 year old children than in typical adults. Moreover, we found that the ability to judge orientation in WS improves with increasing mental age, but not chronological age. These results suggest that orientation discrimination in WS is developmentally arrested, as opposed to abnormal or delayed.
威廉姆斯综合征（WS）是一种以视空间认知缺陷为特征的发育障碍。为了了解这种缺陷的本质，我们研究了 WS 患者如何感知视觉方向，这是一种与物体识别相关的基本能力。我们将 WS 参与者与正常发育的儿童（3-6 岁）和典型成年人在一个定向辨别任务中进行比较，该任务使用了四种刺激类型（小圆形、大圆形、共线拉长和平行拉长光栅）。我们测量了定向辨别阈值和正交错误（即镜像反转错误）的比例。我们评估了这些指标（1）如何受到刺激条件的调节，以及（2）如何随年龄或心理年龄而变化。我们发现，WS 患者的定向感知与正常发育的儿童相当。在所有参与者群体中，拉长光栅的定向辨别阈值都优于圆形光栅。对于大圆形光栅，WS 参与者和正常发育的 3-6 岁儿童的正交错误比例明显高于典型成年人。此外，我们发现 WS 患者判断方向的能力随心理年龄的增加而提高，但不受实际年龄的影响。这些结果表明，WS 中的定向辨别是发育性的，而不是异常或延迟的。
