Gomez Gonzalez C M, Clark V P, Fan S, Luck S J, Hillyard S A
Laboratorio de Psicobiologia, Facultad de Filosofia y C.E., Sevilla, Spain.
Brain Topogr. 1994 Fall;7(1):41-51. doi: 10.1007/BF01184836.
In a study of the neural processes that mediate visual attention in humans, 32-channel recordings of event-related potentials were obtained from 14 normal subjects while they performed a spatial attention task. The generator locations of the early C1, P1, and N1 components of the visual evoked response were estimated by means of topographic maps of voltage and current source density in conjunction with dipole modelling. The topography of the C1 component (ca. 85 ms post-stimulus) was consistent with a generator in striate cortex, and this component was unaffected by attention. In contrast, the P1 and N1 components (ca. 95 and 170 ms) exhibited current density foci at scalp sites overlying lateral extrastriate cortex and were larger for attended stimuli than for unattended stimuli. The voltage topographies in the 75-175 ms latency range were modeled with a 5-dipole configuration consisting of a single striate dipole and left-right pairs of dipoles located in lateral extrastriate and inferior occipito-temporal areas. This model was found to account for the voltage topographies produced by both attended and unattended stimuli with low residual variance. These results support the proposal that visual-spatial attention modulates neural activity in extrastriate visual cortex but does not affect the initial evoked response in striate cortex.
在一项关于介导人类视觉注意力的神经过程的研究中，从14名正常受试者身上获取了事件相关电位的32通道记录，当时他们正在执行一项空间注意力任务。视觉诱发电位早期C1、P1和N1成分的发生器位置通过电压和电流源密度地形图结合偶极子模型进行估计。C1成分（刺激后约85毫秒）的地形图与纹状皮层中的一个发生器一致，并且该成分不受注意力的影响。相比之下，P1和N1成分（约95和170毫秒）在覆盖外侧纹外皮层的头皮部位表现出电流密度焦点，并且对于被关注的刺激比未被关注的刺激更大。在75 - 175毫秒潜伏期范围内的电压地形图用一个由单个纹状偶极子以及位于外侧纹外和枕颞下区域的左右偶极子对组成的5偶极子配置进行建模。发现该模型能够以低残差方差解释由被关注和未被关注的刺激产生的电压地形图。这些结果支持了视觉空间注意力调节纹外视觉皮层中的神经活动但不影响纹状皮层中初始诱发电位的提议。
