title: Attentional modulations of the early and later stages of the neural processing of visual completion.
abstract: The brain effortlessly recognizes objects even when the visual information belonging to an object is widely separated, as well demonstrated by the Kanizsa-type illusory contours (ICs), in which a contour is perceived despite the fragments of the contour being separated by gaps. Such large-range visual completion has long been thought to be preattentive, whereas its dependence on top-down influences remains unclear. Here, we report separate modulations by spatial attention and task relevance on the neural activities in response to the ICs. IC-sensitive event-related potentials that were localized to the lateral occipital cortex were modulated by spatial attention at an early processing stage (130-166 ms after stimulus onset) and modulated by task relevance at a later processing stage (234-290 ms). These results not only demonstrate top-down attentional influences on the neural processing of ICs but also elucidate the characteristics of the attentional modulations that occur in different phases of IC processing.
authors: 1] Department of Psychology, Sun Yat-Sen University, China [2] CAS Key Laboratory of Brain Function and Disease, and School of Life Sciences, the University of Science and Technology of China, Hefei, Anhui, China.
authors: Xiang
authors: X
authors: Wu
authors: Department of Psychology, Sun Yat-Sen University, China.
authors: Liang
authors: L
authors: Zhou
authors: Department of Psychology, Sun Yat-Sen University, China.
authors: Cheng
authors: C
authors: Qian
authors: Department of Psychology, Sun Yat-Sen University, China.
authors: Lingyu
authors: L
authors: Gan
authors: CAS Key Laboratory of Brain Function and Disease, and School of Life Sciences, the University of Science and Technology of China, Hefei, Anhui, China.
authors: Daren
authors: D
authors: Zhang
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D013702:Temporal Lobe / Q000502:physiology*; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*