Department of Ophthalmology, Nationwide Children's Hospital, Columbus, OH, USA.
Brain Res. 2011 Jan 7;1367:162-9. doi: 10.1016/j.brainres.2010.10.082. Epub 2010 Oct 28.
The purpose of this study was to ascertain whether visual acuity or contrast sensitivity function (CSF) is proportional to visual cortical function based on fMRI volume and level of activation or Z-score. Forced choice procedures were utilized to measure the monocular log minimal angle of resolution (logMAR) visual acuity and CSF. The CSF data were collapsed into a single index by the use of weighted mean contrast sensitivity (WMCS), being defined as the mean of the products of each spatial frequency multiplied by its corresponding contrast sensitivity. fMRI data had been obtained with a 1.5 T GE Signa scanner with visual stimuli including 1.0 and 2.0 c/deg vertical sinusoidal gratings. Subjects consisted of eight normal adults and five amblyopic patients, with the amblyopic subjects added to gauge whether the outcome was due to a restricted range of scores or the small number of study participants. In normal subjects, the fMRI volume and level of activation exhibited no statistically significant correlation with visual acuity at P<0.05. Statistically significant correlations were obtained between WMCS and fMRI volume (R=0.765, P=0.027) and fMRI level of activation (R=0.645, P=0.007), with right eye stimulation using the 1.0 c/deg grating. On the whole, statistically significant correlations between WMCS and fMRI parameters were maintained when subject age was held constant and when data from the five amblyopic subjects were included to expand the range of values and increase the number of data sets for analysis. fMRI volume and Z-score were more closely associated with the CSF, as defined by WMCS, than visual acuity. The results suggest that the CSF reflects the underlying visual cortical cells responsible for fMRI volume and the level of activation.
本研究旨在确定基于 fMRI 体积和激活水平或 Z 分数，视力或对比敏感度功能（CSF）是否与视觉皮层功能成正比。使用强迫选择程序测量单眼对数最小角度分辨率（logMAR）视力和 CSF。通过使用加权平均对比敏感度（WMCS）将 CSF 数据合并为单个指数，WMCS 定义为每个空间频率与其相应对比敏感度乘积的平均值。使用 1.5 T GE Signa 扫描仪获得 fMRI 数据，视觉刺激包括 1.0 和 2.0 c/deg 垂直正弦光栅。受试者包括 8 名正常成年人和 5 名弱视患者，加入弱视患者以评估结果是由于分数范围有限还是研究参与者人数较少。在正常受试者中，fMRI 体积和激活水平与视力在 P<0.05 时无统计学显著相关性。WMCS 与 fMRI 体积（R=0.765，P=0.027）和 fMRI 激活水平（R=0.645，P=0.007）之间存在统计学显著相关性，右眼刺激使用 1.0 c/deg 光栅。总体而言，当控制受试者年龄并纳入 5 名弱视受试者的数据以扩大值范围并增加数据集数量进行分析时，WMCS 与 fMRI 参数之间保持统计学显著相关性。fMRI 体积和 Z 分数与 WMCS 定义的 CSF 的相关性比视力更密切。研究结果表明，CSF 反映了负责 fMRI 体积和激活水平的潜在视觉皮层细胞。
