[ 戻る ]
- 2001 Conference Abstracts
- PI
- title
- Abstract
- PI
- title
- Abstract
- PI
- title
- Abstract
- 筆頭
- title
- Abstract
- 筆頭
- title
- Abstract
- 筆頭
- title
- Abstract
- PI
- title
- Abstract
- Chikako Kato
- Activation during endogeneous orientation of visual attention using symbolic pointers in the human parietal and frontal cortices: A functional magnetic resonance imaging study
- Brain activation induced by endogenous orienting with a motor response was investigated by functional magnetic resonance imaging. We conducted four cued-attention experiments in which peripheral attention was caused by one of three symbolic pointers (eyes, squares as artificial eyes, or an arrow) that was predictive or not predictive of the target location. Attentional shift caused by the predictive and non-predictive cues induced right and left parietal activation across cue modalities, respectively. Regardless of the predictability of the target location, the eyes and arrow induced left parietal and frontal activation, and the arrow induced left parietal activation more than the squares. These results suggested that the left parieto-frontal network was involved in motor attention caused by natural or familiar pointers, whereas the right parietal cortex was involved in endogenous orienting.
- Kayako Matsuo
- Visual language and handwriting movement: functional magnetic resonance imaging at 3 tesla during generation of ideographic characters
- A functional magnetic resonance imaging experi-mentat 3 tesla was performed to investigate the collaborativemechanism between visuospatial processing and motor execu-tionin performing visual language generation tasks. JapaneseKanji, ideographic characters,were utilized to design tasks. The bilateral border portions between the inferior parietal lob-ule and the occipital lobe were involved during a Kanji puzzle task, which required subjects to combine several parts into a Kanji. The higher motor areas, such as the premotor areas and the pre-supplementary motor areas, were also activated bilat-erally during the puzzle task. The parieto-occipital activation may be related to analysis of configuration or segmentation/integration of Kanji figures. Activation in the higher motor areas may be induced by cognitive components related to motor function to perform the visuospatial language task, such as intense reference for displayed characters and finding a proper character for puzzle solution. A collaborative mechanism in these areas may explain the effectiveness of tactile reading inletter recognition by patients with pure alexia or kinesthetic facilitation by Kanji users when recalling difficult Kanji.
- Shigeru Muraki
- An attempt for coloring multichannel MR imaging data
- This is an elementary research into assigning color values to voxels of multi-channel magnetic resonance imaging (MRI) volume data. The MRI volume data sets obtained under different scanning conditions are transformed into components by independent component analysis (ICA), which enhances the physical characteristics of the tissue. The transfer functions for generating color values from the independent components are obtained by using a radial basis function network, a kind of neural net, by training the network with sample data chosen from the Visible Human female data set (VHF). The resultant color volume data sets correspond well with the full-color cross-sections of the Visible Human data sets
- 松尾香弥子
- Ideographic characters call for extra processing to correspond with phonemes
- Cortical areas used in the copying of Japanese ideographiccharacters and syllabic characters were studied using functionalmagnetic resonance imaging in healthy volunteers. Complexityof characters was controlled to illustrate differences resultingfrom character to sound conversion differences between theideographic and syllabic characters. Statistical comparisonsindicated extensive activation in the fusiform gyrus, posteriorportions around the intraparietal sulcus and in the conjunctionarea of BA 6, 9 and 44 (which is assumed to be Exner's area)during the copying of ideographic characters. These findingssuggested that indirectness between ideographic charactersand their pronunciation demands extra processing such assemantic mediation and intensive grapheme processing incomparison with syllabic characters.
- 田中茂樹
- Neural substrates involved in imitating finger configurations: an fMRI study
- Imitation plays a very important role in human cognition. Because previous neuroimaging studies on human imitation used rather simple actions as target stimuli, some aspects of imitation such as perceiving target actions or manipulating one's own mental image could not be studied. We used complicated non-symbolic (S-) and symbolic (S+)finger configurations as target stimuli in order to study the neural substrates involved in the perception of target actions and mental image manipulation during imitation. Bilateral supramarginal gyrus activation was detected when the S- condition was compared with the S+ condition. Our result suggests the involvement of the supramarginal gyrus especially for the imitation of novel actions.
- 中井敏晴
- BOLD contrast on a 3T magnet-detectability of the motor areas
- To predict the potential and the limitations of functional MRI (fMRI) with a very high field magnet, the detectability and reproducibility of activation were evaluated by comparing the activation induced by a sequential finger movement task at 1.5 T with that at 3 T. The detectability of the premotor area, supplementary motor area (SMA), and ipsilateral sensorimotor area (SM1) showed significant improvement at 3 T. On the other hand, the detectability of contralateral SM1 was not significantly different between 1.5 and 3 T. The degree of activation was proportional to task demand in the ipsilateral SM1 and SMA, whereas that in the contralateral SM1 and SMA was not. FMRI with a 3 T magnet has greater potential for detection of neuronal activation as a functional network. These observations indicated that task demand and static magnetic field strength should be considered in interpretation of fMRI data for clinical usage.
- Toshiharu Nakai
- Development of 3D stereo viewer for high resolution data
- In order to visualize high resolution (3D) data as a stereogram,a real time volume rendering system using a hardware graphic board and a conventional PC was developed. A 2563 data set could be visualized at a redrawing rate of 12Hz and a 5123 data set at 2.5Hz. It was demonstrated that stereogram visualization using volume graphic paameters such as level,window,transfer function for opacity and color map coordinate direction.