These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Brain mechanisms underlying visual perception and visual mental imagery of Chinese pseudo-characters: an event-related potential study.
    Author: Qiu J, Li H, Liu Q, Zhang Q.
    Journal: Brain Res; 2007 Dec 12; 1184():202-9. PubMed ID: 18028887.
    Abstract:
    The aim of this study was to compare spatiotemporal cortical activation patterns that underlie the processing of visual perception and visual mental imagery of Chinese pseudo-characters. Event-related brain potentials (ERPs) were measured when 14 healthy Chinese college students performed a pseudo-character stroke judgment task. Results showed that visual mental imagery elicited a more negative ERP deflection (N240) than visual perception in the 150- to 250-ms time window after onset of the stimuli. Maps of the difference wave (mental imagery-visual perception) showed strong activity in the right frontal regions. Dipole analysis revealed that the generator of N240 was localized in the right parahippocampal cortex and possibly related to forming a visual mental imagery of the pseudo-character on the basis of initial stimuli identification and classification. Then in the time window between 400 and 600 ms, a greater negativity (N520) in visual mental imagery as compared to visual perception was detected over the right frontocentral scalp regions. Moreover, dipole source analysis of the difference wave (mental imagery-visual perception) indicated that a generator was localized in the right temporal-occipital junction (BA18), which appeared to reflect the cognitive processes of character reconstruction and stroke searching in the visual mental imagery of the pseudo-character. The results showed that the visual mental imagery of Chinese pseudo-characters might be related to the right parahippocampal cortex, and activation of the right temporal-occipital junction was possibly related to accomplishing the stroke judgment task in the visual mental imagery.
    [Abstract] [Full Text] [Related] [New Search]