Distinguishing excitatory and inhibitory transcallosal interactions.

人类的大脑分为两个半球，它们相互作用来处理信息并控制身体。大量的研究描述了两个大脑半球的专门化方式。例如，左半球主要负责语言功能，而右半球则擅长空间判断。然而，大多数人类认知需要两个半球的贡献，它们以部分合作和部分竞争的方式相互交流。了解大脑半球之间的这种交流是如何发生的，对于开发以有益方式调节大脑活动的新方法至关重要，例如通过无创大脑刺激。最近，许多新方法被开发出来，用一种叫做脑磁图（MEG）的机器来检测大脑的电活动。脑磁图记录神经元产生的电磁波，具有较高的时空精度。通过同时分析两个大脑区域的活动，研究人员可以检查信息在不同时间和方向上在它们之间传递的程度。我们实验室的研究表明，区分合作和竞争的相互作用是可能的，这可能表现在不同的大脑信号中。为了验证对这些信号的分析，我们将利用大脑的一些众所周知的不对称性，其中信息从大脑半球传递到另一个半球（合作互动），其中一个半球抑制另一个半球（竞争）。例如，左运动皮层控制身体的右侧，右运动皮层控制身体的左侧。当某人移动右手时，他们的左运动皮层会通过脊髓向右手发送兴奋信号，但同时也会向右运动皮层发送抑制信号，以防止其干扰。通过测量手部运动时的电活动，并将其与其他已知的竞争指标进行比较，我们将验证新技术在检测竞争相互作用方面的应用。另一种不对称发生在周边视觉。左脑接收来自右视野的视觉信息，反之亦然。因为左半球是语言的主导，所以出现在左视野（到右半球）的单词信息必须转移到左半球，但相反的情况发生得少得多。另一方面，右半球是决定面孔的主要部分，所以呈现在右视野（左半球）的关于面孔的信息以不同的方式传递到右半球。通过比较文字和面部的相互作用，我们将验证新技术的使用，以检测半球之间信息的不对称传递。

The human brain is divided into two halves, or hemispheres, which interact with each other to process information and control the body. A large amount of research has characterized the ways in which the two hemispheres are specialized. For example, the left hemisphere is dominant for language functions, while the right is superior at spatial judgments. However, most human cognition requires contributions from both hemispheres, and they communicate with each other in ways that are partially cooperative and partially competitive. Understanding how this communication happens between hemispheres is critical for the development of new methods to modulate brain activity in beneficial ways, such as through noninvasive brain stimulation. Recently, many new methods have been developed to detect the brain's electrical activity with a machine called magnetoencephalography (MEG). MEG records the electromagnetic waves generated by neurons with high spatial and temporal precision. By analyzing the activity in two brain regions simultaneously, researchers can examine the degree to which information is transferred between them at different times, and in which direction. Our laboratory's studies have suggested that it may be possible to distinguish cooperative and competitive interactions, which may manifest in different brain signals. To validate the analysis of these signals, we will take advantage of some well-known asymmetries of the brain, in which information is transferred from brain hemisphere to the other (a cooperative interaction), and in which one hemisphere suppresses the other (competition). For example, the left motor cortex controls the right side of the body, and the right motor cortex controls the left side of the body. When someone moves their right hand, their left motor cortex sends an excitatory signal to the right hand via the spinal cord, but also sends an inhibitory signal to the right motor cortex to prevent it from interfering. By measuring electrical activity during hand movements, and comparing it with other known measures of competition, we will validate the use of new techniques to detect competitive interactions. Another asymmetry occurs with peripheral vision. The left side of the brain receives visual information from the right visual field, and vice versa. Because the left hemisphere is dominant for language, information about words presented in the left visual field (to the right hemisphere) must be transferred to the left hemisphere, but the reverse occurs much less. On the other hand, the right hemisphere is dominant for making decisions about faces, so information about faces presented to the right visual field (left hemisphere) is differentially routed to the right hemisphere. By comparing interactions for words and faces, we will validate the use of new techniques to detect asymmetrical transfer of information between the hemispheres.