A FMRI Study About The Affective To Effect The Cognitive-control In Depression

Depression is a mental disorder that is commonly-occurred,it makes the depressionpatients and their families have heavy spirit and social and economic burden. Thepathogenesis of depression is complicated, so many researchers at home and abroad areengaged in the studies. The cognitive mechanism of depression is one of hot topics recently.Aron Beck, the American psychologist, addressed that depression resulted from negativecognitive schema in1976. And the following studies confirmed that depressed patients,because of their negative cognitive schema, were apt to choose negative information thatconsistent to their negative schema when processing external information, that leaded to thegeneration and development of depression. The bias in depressed patients might reflect thelack of the cognitive control function,the negative emotion processing will not beeffective,lead to negative emotions processing over. The bias might also reflect the enhancedprocessing of negative emotional stimuli. However, how iscognitive control and affective toproduce negative cognitive processing bias,cause the major depression? The researchs couldnot give complete explanations now. Therefore, by the technology of behavior and fMRI, thisstudy observed the mechanism of interaction between affective and cognitive control innormal and depressed in dividuals during three emotion-oddball tasks(neutral and negativeemotion stimuli). The results and conclusions were obtained as follows:1. When subjects do the classical oddball target task, the depression patients andnormal subjects are no significant differences in reaction time and accuracy; when thestandard stimulus are sad face pictures, the activation areas and intensity of the normalsubjects and depression patients are significant difference higher than the standard stimulusare neutral face picture; when neutral face pictures are standard stimulus, the activationareas and intensity of depression patients are lower than normal subjects,especially thesuperior frontal gyrus in dorsolateral prefrontal and lobulus parietalis;when the standardstimulus are sad face pictures, the activation areas and intensity of depression patients arehigher than normal subjects,especially the anterior cingutate. 2. When subjects do the oddball task about the emotion face, the depression patientsand normal subjects are no significant differences in reaction time and accuracy; theactivation areas and intensity of oddball stimulus of normal subjects are lower than standardstimulus,the areas include cerebellum, occipital gyrus and the right side of Roland DickIsland cover, these areas are lowest, additionally, central cingulate gyrus, the right side ofpostcentral gyrus activity also decreased significantly; but the activation areas and intensityof oddball stimulus of depression patients are higher than standard stimulus, that includefrontal gyrus, middle frontal gyrus, middle temporal gyrus and angular gyrus, but theactivation of cortex region relate to the vision function is decreas, such as middle occipitalgyrus; under the standard stimulus, the activion of depression patients is lower than normalsubjects, such as middle frontal gyrus, inferior frontal gyrus, orbital gyrus, the anteriorcingulate cortex, postcentral gyrus and the supplementary motor area; under the oddballstimulus the activation of depression patients is higher than normal subjects, the areasinclude frontal gyrus, precentral gyrus, postcentral gyrus, middle occipital gyrus, thecerebellum, but there still some areas lower than normal subjects, such as hippocampus andparahippocampal gyrus and other limbic regions.3. When subjects do the oddball task with interference, the depression patients andnormal subjects are no significant differences in reaction time and accuracy; when normalsubjects under the oddball stimulus, the activation of brain is lower than under the standardstimulus, the areas include frontal gyrus, ventromedial prefrontal, anterior cingulate andoccipital back; when the depression patients under the oddball stimulus, the activation ofbrain is higher than under the standard stimulus, the areas include frontal gyrus, occipitalgyrus, the central front and rear back; under the standard stimulus the activation ofdepression patient is lowet than normal subjects, such as frontal gyrus, anterior cingulatecortex, inferior frontal gyrus, precentral gyrus and postcentral gyrus; under the oddballstimulus, the activation of depression patients is higher than normal subjects, the areasinclude frontal gyrus and middle occipital gyrus.Conclusion：Depression patients enhance the emotional processing of negative lifeevents, and the lack of cognitive control can not inhibit the enhanced emotional processing.So this situation cause the patient to produce more negative emotions, lead to depression.