A FMRI Study On Attention Executing Function Of Depression Patient

The study used the Counting Stroop by presenting visual stimulus (number and symbol) in the condition of behavior experiment and event-related functional magnetic resonance imaging (fMRI) experiment in order to show the difference in aspect of activation areas and voxels between depression patients and normal subjects. We designed three levels of neutral, congruent and incongruent to reveal the neuro-basis of attention executing function disorder of depression patients and to test the hypothesis on the relation of central executing function and attention executing function disorder with the corresponding brain areas of depression patients from the point of cognitive neuro-science.The results were as follows. Reaction time has been observed significant difference between normal subjects and depression patients in three different conditions, which was probably related with attention executing function disorder of depression patients . The study had verified both two circle-roads of consciousness and the separate viewpoints of automatic/unautomatic processing. And the study also explored the functional fixed position of central brain areas of attention executing function of depression patients, voxel volumes of interesting regions during attention executing process by the way of enven-related fMRI.The main findings of the study were as follow as:(1) The interference effect was successfully produced in the Counting Stroop, which showed that reaction time of incongruent group was longer than congruent group. So it was a good way to study attention-executing function by fMRI.(2) Both normal subjects and depression patients demonstrated activation of various areas including premotor cortex, anterior frontal cortex, anterior cingulate cortex, posterior cingulate cortex and insula, but depression patients showed more than normal subjects in respect of activation degree and left and right activation voxels in certain specific areas under three different conditions.(3) Activation voxels of left and right premotor cortex of depression patients were obviously lower than normal subjects, especially left premotor cortex decreased in the incongruent condition. It meant that the function of series movement integration and programmed process probably reduced when depression patients reacted to stimulus(4) The function of anterior frontal areas of depression patients decreased in the general executing process, and there were increasing tendency in the deep executing process when the patients executed the complex interference information.(5) The launch, regulation and reactive select attention function of anterior cingulate cortex of depression patient decreased in the condition of general executing process. When the condition was deep executing process, the function of anterior cingulated cortexincreased to induce the wrong to correct on-line response.(6)The posterior cingulate cortex of depression patients, which could improve adequate response and inhibited inadequate response decreased in the general executing process condition, and in the deep executing process condition, they needed more activation in posterior cingulated cortex to resist the affect of interference because it was more easily influenced by unconcerned information.(7) The activation of insula of depression patients decreased in the general executing process condition, while in the deep executing process condition, there were increased activation of functional areas in the non-superior brain.(8)The results of study supported the views of two circle-roads of consciousness and the separate viewpoints of automatic/unautomatic processing. The study initially explored the basic of neuro-physiological of attention executing function disorder of depression patients and the potential neuropsycho-physiological mechanism of the Counting Stroop task.