| Presentation | 2011-01-24 Neural representation of object-centered coordinates in humans : an fMRI study Kenji OGAWA, Toshio INUI, |
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| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | Several types of reference frames exist in the human brain. Previous neuropsychological case studies of hemi-neglect, in which the patient often neglects the right side of visually presented objects, have indicated the existence of neural representation of object-based coordinates in humans. The parieto-premotor regions, especially those of the right hemisphere, have consistently been reported as responsible for hemi-neglect. However, whether these areas represent visually presented stimuli in an object-centered reference frame remains unclear. We aimed to reveal neural representation of object-based coordinates in humans, using functional MRI (fMRI) together with multi-voxel pattern analysis (MVPA). In our experiment, participants were presented with visual stimuli consisting of two crossed lines, and they judged whether the vertical line was located to the left or right of a central fixation point (retinotopic coordinates) or a horizontal line of the stimulus (object-centered coordinates). For MVPA, we tried to classify the two possible positions (left or right) in either retinal- or object-based coordinates using multi-voxel pattern activities of regions of interest (ROIs). The linear support vector machine (SVM) was used as a classifier. A significantly above-chance decoding accuracy was found in the early visual areas, bilaterally, for retinal coordinates. In contrast, significant classification accuracies for object-centered coordinates were found in the ventral premotor cortex (PMv) in the right hemisphere, which were independent of retinal coordinates as well as a shift in visuo-spatial attention. Taken together, these findings suggest the existence of an object-centered reference frame in the right PMv. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | fMRI / multi-voxel pattern analysis (MVPA) / object-centered coordinates / ventral premotor cortex (PMv) |
| Paper # | NLP2010-137,NC2010-101 |
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| Conference Information | |
| Committee | NC |
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| Conference Date | 2011/1/17(1days) |
| Place (in Japanese) | (See Japanese page) |
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| Topics (in Japanese) | (See Japanese page) |
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| Registration To | Neurocomputing (NC) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Neural representation of object-centered coordinates in humans : an fMRI study |
| Sub Title (in English) | |
| Keyword(1) | fMRI |
| Keyword(2) | multi-voxel pattern analysis (MVPA) |
| Keyword(3) | object-centered coordinates |
| Keyword(4) | ventral premotor cortex (PMv) |
| 1st Author's Name | Kenji OGAWA |
| 1st Author's Affiliation | Asada project, ERATO, Japan Science and Technology Agency() |
| 2nd Author's Name | Toshio INUI |
| 2nd Author's Affiliation | Asada project, ERATO, Japan Science and Technology Agency:Graduate School of Informatics, Kyoto University |
| Date | 2011-01-24 |
| Paper # | NLP2010-137,NC2010-101 |
| Volume (vol) | vol.110 |
| Number (no) | 388 |
| Page | pp.pp.- |
| #Pages | 6 |
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