title: Spatiotemporal differences between cognitive processes of spatially possible and impossible objects: a high-density electrical mapping study.
abstract: Differences in cognitive processing between spatially possible and impossible figures were investigated using event-related potentials (ERPs). Two types of figures with identical luminance and equivalent spatial frequency were used as visual stimuli: possible three-dimensional figures (drawn with perspective and existing in the three-dimensional world) and impossible figures (drawn with perspective but not existing in the three-dimensional world). High-density electroencephalographic recording (72 channels) was performed for analysis of ERPs accompanying perception of each figure type; amplitude differences between the conditions were considered neurophysiologic correlates to perceptual differences between possible and impossible objects. Low-resolution brain electromagnetic tomography (LORETA) was used to identify the current source related to the differences. Compared with impossible three-dimensional figures, perception of possible figures showed a significant negative potential increase in the right inferior occipitotemporal region between 350 and 389 ms of latency. The current source was localized to the right fusiform gyrus. The results suggest that right fusiform gyrus is involved in discrimination between spatially possible and impossible objects.
authors.affiliation: Department of Psychiatry, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Shigemura
authors.forename: Aihide
authors.initials: A
authors.lastname: Yoshino
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Soichiro
authors.initials: S
authors.lastname: Nomura
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003071:Cognition / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology*; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods*; D013028:Space Perception / Q000502:physiology*; D013997:Time Factors