Jacques Corentin, Rossion Bruno
Laboratoire de Neurophysiologie, University of Louvain, Louvain-la-Neuve, Belgium.
J Vis. 2006 Feb 17;6(2):154-62. doi: 10.1167/6.2.6.
A recent event-related potential (ERP) study showed that the occipitotemporal component N170 recorded to a face stimulus appearing in the peripheral visual field is strongly reduced when subjects are concurrently fixating another face stimulus. This suggests that concurrently presented face stimuli compete for neural representation in the occipitotemporal cortex between 100 and 200 ms following stimulus onset. We tested whether this competition can be observed for a foveally presented face stimulus appearing next to either two peripheral face pictures or two peripheral control stimuli. The N170 in response to the fixated central face stimulus was substantially reduced (approximately 20% of signal) when it was presented next to peripheral face stimuli. The response suppression was smaller in magnitude than in a previous study where the competing stimulus was fixated and the target stimulus appeared in the periphery. Besides providing a better control for attentional and eye movement confounds, the concurrent stimulation paradigm for fixated face stimuli in ERPs offers a powerful tool to investigate the time course and the nature of the interactions between face and nonface object representations.
最近一项与事件相关电位（ERP）的研究表明，当受试者同时注视另一个面部刺激时，记录到的出现在外周视野中的面部刺激的枕颞成分N170会显著降低。这表明，在刺激开始后的100到200毫秒之间，同时呈现的面部刺激会在枕颞皮质中争夺神经表征。我们测试了在注视点呈现的面部刺激旁边出现两个外周面部图片或两个外周对照刺激时，是否能观察到这种竞争。当中央注视的面部刺激出现在外周面部刺激旁边时，其诱发的N170显著降低（约为信号的20%）。与之前竞争刺激被注视而目标刺激出现在外周的研究相比，本研究中反应抑制的幅度较小。除了能更好地控制注意力和眼动混淆因素外，ERP中注视面部刺激的同时刺激范式为研究面部与非面部物体表征之间相互作用的时间进程和性质提供了一个强大的工具。
