An fMRI Study of Word Reading and Colour Recognition in Different Quadrant Fields
Tadashi Ino*, 1, Ryusuke Nakai2, Takashi Azuma2, Kazuki Tokumoto1, Kiyohide Usami1, Toru Kimura1
Identifiers and Pagination:Year: 2008
First Page: 56
Last Page: 64
Publisher ID: TONIJ-2-56
Article History:Received Date: 9/6/2008
Revision Received Date: 16/6/2008
Acceptance Date: 20/6/2008
Electronic publication date: 12/8/2008
Collection year: 2008
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
This fMRI study analyzed activations for processing of word and colour, which were presented in each of the four quadrants, to investigate anatomical segregation between colour and orientation processing and also to examine the effect of visual stimulus position on brain activations. Main effect of visual category was found in the bilateral extrastriate cortices extending to the left visual word form area (word > colour) and small area of the right ventrolateral prefrontal cortex (colour > word). ROI analysis showed that there was a tendency that V4α, not V4/8, showed a greater response to colours than to words. Main effect of visual fields was found in early visual areas, which showed greater responses to the left than to the right field stimuli and also to the lower than to the upper field stimuli. No significant interactions between visual category and visual fields were found.