Séverac Cauquil Alexandra, Ory-Magne Fabienne, Jardiné Vincent, Galitzky Monique, Rosito Maxime, Brefel-Courbon Christine, Celebrini Simona
CerCo, Centre de Recherche Cerveau et Cognition, Université de Toulouse UPS, CNRS-UMR 5549, Toulouse, France.
INSERM UMR1214, Imagerie cérébrale et handicaps neurologiques, Toulouse, France; Department of Neurology, University Hospital of Toulouse, Toulouse, France.
Brain Res. 2017 May 15;1663:161-165. doi: 10.1016/j.brainres.2017.03.017. Epub 2017 Mar 19.
3D perception, which is necessary for an optimal navigation in our environment, relies on 2 complementary kinds of cues; binocular cues allowing precise depth localization near the point of visual interest and monocular ones that are necessary for correct global perception of visual space. Recent studies described deficient binocular 3D vision in PD patients; here we tested 3D vision in PD patients when based on monocular cues (m3D). Sixteen PD patients and 16 controls had to categorize visual stimuli as perceived in 2D (flat) or 3D (with depth). Both performance and response times were measured. EEGs were recorded to extract Visual Evoked Potentials. Effects of PD were tested by comparing psychometric and electrophysiological data obtained in controls and PD patients evaluated without dopaminergic treatment. Effects of Levodopa were tested by comparing data in PD patients with and without dopaminergic treatment. We didn't find statistical differences between PD patients and controls' performance. Severity of PD (UPDRS III) in OFF condition is positively correlated with P1 amplitudes and latencies for both 2D and m3D stimuli. Levodopa administration didn't modify either PD patients' performances although it increases principal visual components latencies for both 2D and m3D stimuli. Unlike binocular 3D vision, monocular 3D vision does not seem to get affected by PD. However given the correlation between severity of PD and VEPs' modifications, alteration of visual cortical processing might have nonetheless begun. PD patients reporting trouble in perceiving space must rely more on m3D cues present in the environment.
三维感知对于在我们的环境中进行最佳导航是必要的，它依赖于两种互补的线索：双眼线索允许在视觉兴趣点附近进行精确的深度定位，而单眼线索对于正确全局感知视觉空间是必需的。最近的研究描述了帕金森病患者存在双眼三维视觉缺陷；在这里，我们测试了帕金森病患者基于单眼线索（m3D）时的三维视觉。16名帕金森病患者和16名对照者必须将视觉刺激分类为二维（平面）或三维（有深度）感知。测量了表现和反应时间。记录脑电图以提取视觉诱发电位。通过比较在未接受多巴胺能治疗的对照者和帕金森病患者中获得的心理测量和电生理数据，测试帕金森病的影响。通过比较接受和未接受多巴胺能治疗的帕金森病患者的数据，测试左旋多巴的影响。我们没有发现帕金森病患者和对照者在表现上的统计学差异。帕金森病患者在非服药状态下的严重程度（统一帕金森病评定量表III）与二维和m3D刺激的P1波幅和潜伏期呈正相关。尽管左旋多巴给药增加了二维和m3D刺激的主要视觉成分潜伏期，但并未改变帕金森病患者的表现。与双眼三维视觉不同，单眼三维视觉似乎不受帕金森病的影响。然而，鉴于帕金森病严重程度与视觉诱发电位改变之间的相关性，视觉皮层处理的改变可能已经开始。报告在感知空间方面有困难的帕金森病患者必须更多地依赖环境中存在的m3D线索。
