Anderson T J, Jenkins I H, Brooks D J, Hawken M B, Frackowiak R S, Kennard C
MRC Cyclotron Unit, Hammersmith Hospital, London, UK.
Brain. 1994 Oct;117 ( Pt 5):1073-84. doi: 10.1093/brain/117.5.1073.
To identify cortical regions activated during saccades and visual fixation, regional cerebral blood flow (rCBF) was measured in eight healthy subjects using C15O2 PET during the performance of three tasks: (i) central fixation; (ii) reflexive saccades to random targets; (iii) remembered saccades to locations of recent target appearance. Significant rCBF increases were identified using analysis of covariance and the t statistic (P < 0.001). Compared with central fixation there was activation of striate and extra-striate cortex, posterior parietal cortex (PPC) and frontal eye fields (FEF) during both reflexive and remembered saccades. During remembered saccades there was additional activation of supplementary motor area (SMA), insula, cingulate, thalamus, midbrain, cerebellum and right superior temporal gyrus (Brodmann's area 22). Compared with the individual saccadic tasks, central fixation activated extensive regions of ventromedial (areas 10, 11 and 32) and anterolateral (areas 8, 9, 10, 45 and 46) prefrontal cortex, and foveal visual cortex. We conclude that FEF and PPC are associated with the generation of both reflexive and remembered saccades, with SMA additionally involved during remembered saccades. Sustained voluntary fixation is mediated by prefrontal cortex.
为了确定扫视和视觉注视过程中被激活的皮质区域，我们使用C15O2正电子发射断层扫描（PET）技术，在8名健康受试者执行三项任务的过程中测量了局部脑血流量（rCBF）：（i）中央注视；（ii）对随机目标的反射性扫视；（iii）对近期目标出现位置的记忆性扫视。使用协方差分析和t统计量（P < 0.001）确定了rCBF的显著增加。与中央注视相比，在反射性和记忆性扫视过程中，纹状和纹外皮质、顶叶后皮质（PPC）和额叶眼区（FEF）均被激活。在记忆性扫视过程中，辅助运动区（SMA）、脑岛、扣带回、丘脑、中脑、小脑和右侧颞上回（布罗德曼22区）也有额外激活。与个体扫视任务相比，中央注视激活了腹内侧（10区、11区和32区）和前外侧（8区、9区、10区、45区和46区）前额叶皮质以及中央凹视觉皮质的广泛区域。我们得出结论，FEF和PPC与反射性和记忆性扫视的产生有关，SMA在记忆性扫视过程中也有参与。持续的自主注视由前额叶皮质介导。
