Human brain responses to different image contrasts.
Human brain responses to different image contrasts.
复制标题
人脑对不同图像对比度的反应。
DOI：
10.1016/0042-6989(94)90035-3
复制
发表时间：
1994
期刊：
影响因子：
1.8
通讯作者：
Purdy,PD
中科院分区：
文献类型：
--
作者：
Srebro,R;Oguz,RM;Purdy,PD
人脑活动是通过动态随机点显示来诱发的，其中方波光栅以固定的间隔出现和消失。光栅的可见性由四种不同对比度之一确定：纹理、立体视差、亮度或颜色。用31个电极测量的头皮场用于估计上皮层电位场。估计程序需要每个受试者的详细解剖数据。这些是从磁共振图像中获得的。使用三维数字化仪和立体定向头帽，将磁共振图像的参考系与诱发电位的参考系准确融合。皮层电位场提供了一个更好的指标，大脑活动的诱发比头皮领域。这些程序还校正了受试者之间头皮和大脑之间的解剖学差异。在两个右利手的女性受试者，诱发活动观察到在左后顶叶和右枕叶，顶叶枕叶和后颞叶皮质。在左顶叶皮层中观察到用于亮度处理的诱发活动，在右顶叶皮层中观察到用于纹理处理的诱发活动，在右颞叶皮层中观察到用于颜色处理的诱发活动，颜色处理对特定对比度具有选择性。
Human brain activity was evoked by a dynamic random-dot display in which a square-wave grating appeared and disappeared at regular intervals. Grating visibility was determined by one of four different contrasts: texture, stereo disparity, luminance, or color. Scalp fields measured with 31 electrodes were used to estimate epicortical potential fields. The estimation procedure required detailed anatomical data for each subject. These were obtained from magnetic resonance images. A three-dimensional digitizer and a stereotactic headgear were used to accurately merge the frame of reference of the magnetic resonance image with that of the evoked potential. Epicortical potential fields provided a better indicator of where brain activity is evoked than did scalp fields. These procedures also corrected for anatomical variations between scalp and brain from subject to subject. In two right-handed female subjects, evoked activity was observed in the left posterior parietal and the right occipital, parieto-occipital and posterior temporal cortices. Evoked activity was observed in the left parietal cortex for luminance processing, in the right parietal cortex for texture processing and in the right temporal cortex for color processing, which was selective for the particular contrast.