title: Electrophysiological correlates of attention-spreading in visual grouping.
abstract: This study examined event-related potentials in a sustained-attention task that involved bilateral stimulus arrays, which were connected or unconnected by a line. Spatial attention was reflected by a large amplitude of posterior event-related potentials at the hemisphere contralateral, rather than ipsilateral, to the attended hemi-field. The earliest attention effect (P1, 100-160 ms poststimulus) was not affected by connectedness. The subsequent attention effect (N2pc, 190-300 ms) was observed when the target feature appeared in the attended hemi-field, whereas this effect was not seen in the early phase (190-250 ms) in the connected condition. The results indicate that the lateralized event-related potential reflects transient attention-spreading in association with perceptual grouping.
authors.affiliation: Faculty of Education, Hokkaido University, Sapporo, Hokkaido, Japan. tetsu@edu.hokudai.ac.jp
authors.forename: Tetsuko
authors.initials: T
authors.lastname: Kasai
authors.forename: Mariko
authors.initials: M
authors.lastname: Kondo
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D004585:Electrooculography / Q000379:methods; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology*