Giaschi D, Lang A, Regan D
Department of Ophthalmology, The Toronto Hospital, Canada.
Vision Res. 1997 Dec;37(24):3531-4. doi: 10.1016/S0042-6989(96)00316-1.
A group of 20 control subjects carried out the following visual tests: Snellen acuity; contrast detection threshold for a temporally unmodulated grating and for a temporally modulated grating; speed threshold for recognising motion-defined dotted letters. Normal limits were defined as 2.5 standard deviations from the respective control means. A patient with Parkinson's disease carried out the tests 12 hr after medication was withheld at a time when symptoms were evident ("off" stage), and after administration of medication when it had taken full effect ("on" stage). Confirming previous reports, contrast detection threshold for the temporally modulated grating was much higher during the "off" stage than during the "on" stage, but contrast detection threshold for the temporally unmodulated grating showed little difference. Speed threshold for recognising motion-defined letters did not, however, fall during the "on" stage. We suggest that magnocellular function is not essential for the recognition of motion-defined form.
一组20名对照受试者进行了以下视觉测试：斯内伦视力；对时间上未调制光栅和时间上调制光栅的对比度检测阈值；识别运动定义的点状字母的速度阈值。正常范围定义为各自对照平均值的2.5个标准差。一名帕金森病患者在停药12小时后症状明显时（“关”期）以及药物充分起效后（“开”期）进行了测试。正如之前的报告所证实的，时间上调制光栅的对比度检测阈值在“关”期比“开”期高得多，但时间上未调制光栅的对比度检测阈值几乎没有差异。然而，识别运动定义字母的速度阈值在“开”期并未下降。我们认为大细胞功能对于识别运动定义的形态并非必不可少。
