关键词: 功能磁共振成像（fMRI）, 任务激活, 相似性度量

Abstract:

The patterns of brain activation vary greatly when brain performing different types of tasks. Based on this, a new method of task differentiation is proposed. The functional Magnetic Resonance Imaging（fMRI） of task state is analyzed based on similarity calculation to measure the degree of differentiation of activation patterns of each brain region when different conditions are performed, and reveal the ability of each brain region to characterize tasks. fMRI data of memory extraction tasks of normal people and bipolar disorder patients are analyzed. Three commonly used similarity measurement methods, namely Pearson correlation analysis, Euclidean distance calculation and cosine similarity, are used to calculate task discrimination of each brain region. The results show that the brain regions with high discrimination are involved in memory, attention and visual information, which indicates the accuracy and scientificity of this method. Bipolar disorder patients have a lower level of task differentiation in areas of the brain responsible for memory and attention, indicating impaired brain function. In addition, it is found that the discrimination calculation based on Pearson correlation analysis performs well. In conclusion, the method of brain activation task discrimination based on similarity analysis can be applied to fMRI analysis of task-state and the corresponding analysis of brain function.

Key words: functional Magnetic Resonance Imaging（fMRI）, task activation, similarity analysis