The Neural Basis Of Metacognition And Abnormal Patterns In Depression

Metacognition is a multi-level complex concept, it includes the knowledge of cognitive evaluation, adjustment and control, and the process and strategy of this evaluation, adjustment and control. More and more empirical and theoretical researchs shown that metacognition play a significant role on depression and its treatment. The most representative of the mood disorder metacognitive theory was proposed by Wells (1994). the self-regulation of Executive Function model (S-REF), this model is that there are three three interacting emotion processing levels:(1) a level of automatic and reflexively driven processing units; (2) a level of attentionally demanding, voluntary processing; (3) a level of stored knowledge or self-beliefs. The processing operations executed by the controlled processing system are guided by self-knowledge or self-beliefs. In the process of emotional processing, interaction between the three level of processing, repeated cycle. This model is that the constantly strengthened of individual original negative metacognitive beliefs lead to depression. With the development of functional magnetic resonance imaging, making it possible to research the neural bases of metacognition. The current study used a combined structural imaging and resting-state functional connectivity (rsFC) analysis to explore the neural basis of metacognition. The present study investigated the neural correlates of individual difference in metacognition of normal people, and then verified the result from depressive patients.The first experiment explored the neural basis of individual differences of metacognition in normal person. There are 110 healthy college students from southwest university take part in our study. Every participants complete the metacognition questionnaire (MCQ-30), depression scales and MRI scanning (resting state and structural MRI). In which the data is out of fifteen subjects (abnormal anatomy, big head moving or invalid questionnaire, etc.). For structural imaging, we analysis the gray matter volume (GMV) using the method of voxel-based morphometry (VBM) for each subject. Multiple regression analysis was performed to investigate which brain region of GMV was associated with metacogition scores and found that regions of right superior temporal gyrus (STG) and the fusiform gyrus (FuG) were significant positive correlation of GMV, namely, the lower metacognitive levels of individuals the larger volume in these regions; at the same time, individual metacognition questionnaire scores was associated with smaller GMV of precentral gyrus(PrG), namely, he lower metacognitive levels of individuals the smaller volume in this region. Further analyses were conducted to investigate the relationship between rsFC and metacognition, using right STG/FuG/PrG as the seed regions. Multiple regression analysis was performed to investigate the rsFC. Interesting, increased correlations between the right STG and areas of the bilateral hippocampus (Hipp) regions was associated with higher metacognition questionnaire scores (lower metacognition level), and decreased correlations between the left PrG and right medial prefrontal (mPFC) regions was associated with higher metacognition questionnaire scores (lower metacognition level).In the second experiment, we investigated the neural mechanisms of individual difference of metacognition in depressive patients,62 patients with moderate to severe depression and 56 normal persons which gender, age, education level matched as control group subjects. They were also asked to fill in the same scales. Compared the GMV/rsFC between patients and normal subjects within the regions identified in experiment 1 and conducted the relation analysis between metacognition and GMV/rsFC for each group. We found that, compared with control group, patients showed significantly increased GMV in the FuG. At the same time, regions of right superior temporal gyrus (STG) and the fusiform gyrus (FuG) were significant positive correlation of individual metacognition questionnaire scores in control group. Moreover, there were significantly positive correlation between the right STG and areas of the bilateral Hipp and significantly negative correlation between the PrG and the mPFC of metacognition level in control group.This study explored the neural basis of metacognitive individual differences and metacognition is associated with depression in a large sample of the normal population, depressive patients, using a combined structural imaging and rsFC analysis approach. To the best of our knowledge, this is the first study of its kind. Combining the results of experiment 1 and 2, we found that the lower metacognitive levels of individuals the larger volume of right STG and FuG, and increased correlations between the right STG and areas of the bilateral Hipp. In addition, that the lower metacognitive levels of individuals the smaller GMV of PrG, and decreased correlations between the left PrG and right mPFC. Especially patients showed significantly increased GMV in the FuG. These interesting findings might provide an biological basis of subtle differences in brain structural alterations associated with depressive long-standing negative metacognitive beliefs when and why healthy individuals would develop sustained negative mood which in turn enhances depressive symptoms, and also provides a physical basis for the metacognitive therapy for depression.