School of Psychological Sciences, University of Haifa, Haifa 3498838, Israel; The Institute of Information Processing and Decision Making, University of Haifa, Haifa 3498838, Israel; Department of Special Education, University of Haifa, 31905 Haifa, Israel.
Department of Ophthalmology, University of Pittsburgh, and Carnegie Mellon University, Pittsburgh, PA, USA.
Brain Cogn. 2024 Feb;174:106106. doi: 10.1016/j.bandc.2023.106106. Epub 2023 Nov 28.
Studies with individuals with developmental dyslexia (DD) have documented impaired perception of words and faces, both of which are domains of visual expertise for human adults. In this study, we examined a possible mechanism that might be associated with the impaired acquisition of visual expertise for words and faces in DD, namely, the atypical engagement of the monocular visual pathway. Participants with DD and typical readers (TR) judged whether a pair of sequentially presented unfamiliar faces or nonwords were the same or different, and the pair of stimuli were displayed in an eye-specific fashion using a stereoscope. Based on evidence of greater reliance on subcortical structures early in development, we predicted differences between the groups in the engagement of lower (monocular) versus higher (binocular) regions of the visual pathways. Whereas the TR group showed a monocular advantage for both stimulus types, the DD participants evinced a monocular advantage for faces and words that was much greater than that measured in the TRs. These findings indicate that the DD individuals have enhanced subcortical engagement and that this might arise from the failure to fine-tune cortical correlates mediating the discrimination of homogeneous exemplars in domains of expertise.
对发展性阅读障碍（DD）个体的研究记录了他们对单词和面孔感知的障碍，而这两者都是成年人视觉专长的领域。在这项研究中，我们研究了一种可能与 DD 中单词和面孔视觉专长习得障碍相关的机制，即单眼视觉通路的异常参与。DD 患者和典型阅读者（TR）判断一对连续呈现的不熟悉面孔或非词是否相同或不同，并且使用立体镜以特定于眼睛的方式显示一对刺激。基于在发育早期对皮质下结构更大依赖的证据，我们预测两组在视觉通路的较低（单眼）和较高（双眼）区域的参与程度上存在差异。尽管 TR 组对两种刺激类型都表现出单眼优势，但 DD 参与者对面孔和单词的单眼优势明显大于 TR 组。这些发现表明，DD 个体的皮质下参与增强，这可能是由于未能微调皮质相关物来调节在专长领域中同质范例的辨别。
