Attention-Dependent Early Cortical Suppression Contributes to Crowding

Subjects: Biology >> Biophysics >> Neurosciences submitted time 2016-05-18

Chen, Juan He, Yingchen Zhu, Ziyun Peng, Yujia Zhang, Xilin Fang, Fang Chen, Juan He, Yingchen Zhu, Ziyun Peng, Yujia Zhang, Xilin Fang, Fang Fang, Fang Fang, Fang Zhou, Tiangang

Abstract： Crowding, the identification difficulty for a target in the presence of nearby flankers, is ubiquitous in spatial vision and is considered a bottleneck of object recognition and visual awareness. Despite its significance, the neural mechanisms of crowding are still unclear. Here, we performed event-related potential and fMRI experiments to measure the cortical interaction between the target and flankers in human subjects. We found that the magnitude of the crowding effect was closely associated with an early suppressive cortical interaction. The cortical suppression was reflected in the earliest event-related potential component (C1), which originated in V1, and in the BOLD signal in V1, but not other higher cortical areas. Intriguingly, spatial attention played a critical role in the manifestation of the suppression. These findings provide direct and converging evidence that attention-dependent V1 suppression contributes to crowding at a very early stage of visual processing.

Peer Review Status:Awaiting Review

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