Temporal property and reference frame of somatosensory active attention genesis

体感主动注意发生的时间特性和参考系

• 批准号: 17530536
• 负责人: HAMADA Yasukazu
• 金额: $ 1.6万
• 依托单位: Okayama Prefectural University (2006)Kanazawa Institute of Technology (2005)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17530536/
• 关键词: somatosensory; attention; magnetoencephalofraphy; non-invasive measurement; vision; evoked magnetic field; リファレンスフレーム

Attention is one of important mechanism in the brain to select sensory information and to facilitate the information processing. However its neuronal mechanism has not been clearly elucidated. Recent studies using fMRI and MEG have reported neuronal substrates correlated to attentional modulation of cortical activities. My previous studies using MEG also reported that cortical activities in the secondary somatosensory area were increased when the stimuli were applied approximately 400ms after subjects started directing their attention to the finger. In the preset study, I investigated temporal properties of attentional modulation of the somatosensory cortical activities when the hands were in the different positions. The subjects were instructed to direct their attention to a hand indicated by a cue, arrow direction, as soon as possible. After the cue lead time, 200, 300, 400 or 500ms, the electrical current was delivered on the attended index finger. Somatosensory magnetic fields evoked by the current stimuli were measured by using a 160 channel whole head type MEG. Equivalent current dipole (ECDs) moments calculated from the measured fields were compared between the parallel and crossed hand position. The mean ECD moment for the secondary somatosensory activations across the subject tended to increase when the stimuli were applied 400 and 500 ms after the cue onset. The result from one of the subjects showed remarkable difference in the temporal property of the attentional modulation between the two hand position conditions. The attentional modulation appeared with delay of approximately 100 ms in the crossed hand potion condition. This delay might be explained by time for calculation of the hand position. After calculation, the attention was directed a spatial point, at which the hand was located. Although somatosensory attention might be directed with reference of spatial frame rather than body coordinates, further analysis is necessary for this consequence.

注意是大脑选择和促进信息加工的重要机制之一。然而，其神经机制尚未明确阐明。最近使用fMRI和MEG的研究报告了与皮质活动的注意力调节相关的神经元基质。我以前使用MEG的研究也报告说，当受试者开始将注意力集中在手指上大约400 ms后施加刺激时，次级躯体感觉区的皮层活动增加。在预设研究中，我研究了手处于不同位置时，躯体感觉皮层活动的注意调制的时间特性。受试者被指示尽快将注意力转移到由箭头方向指示的手。在提示提前时间200、300、400或500 ms之后，电流被递送到被护理的食指上。用160导全头型脑磁图测量电流刺激诱发的体感磁场。等效电流偶极子（ECD）的时刻计算从测量领域之间的平行和交叉的手的位置进行了比较。平均ECD时刻的次级体感激活整个主题往往增加时，施加400和500毫秒后的线索发作的刺激。其中一名被试的实验结果表明，两种手位条件下的注意调制的时间特性存在显著差异。在交叉手位置条件下，注意调制出现约100 ms的延迟。这种延迟可以用计算手位置的时间来解释。经过计算，注意力被引导到手所在的空间点。虽然躯体感觉注意可能与空间框架而不是身体坐标有关，但这一结果还需要进一步的分析。