Research On Aging Of Brain Network Through The Method Of Cross-frequency Couping

The cognitivebehavioral need communicationbetween different brain regions. The cross-frequency coupling method playing an important role in the communication has been widely applied in the experiments. It has three different types, phase-phase coupling, amplitude-amplitude coupling and amplitude-phase coupling, that we summarized the three methods and its calculations. Than we analysis the experimental data which focus on the aging in the visual attention using the cross-frequency coupling.In this experiment, the visual attention study created in two conditions, search condition and pop-out condition, based on the relationship between the target and distractors triangles in the screen with stimulus. In search condition the distractor triangular had the same color and orientation with the target triangular, however in the pop-out condition the distractor triangular had the same orientation while different color with the target triangular. In this experiment, the cross-frequency coupling methods was used to construct the brain networks and to analyze the difference in different condition with aging.The behavioral result showed that the younger have better behavioral performance than the elderly. While whether the younger or the elderly, the behavioral performance is better in the pop-out than search condition. Also, the difference between the two conditions was greater in the elderly than younger. The coupling result of phase-phase coupling in theta showed certain brain coupled model with the coupling value that in anterior of the brain is larger in younger than elderly, while in the posterior the coupling value is larger in the elderly. Also, the coupling value in the anterior of the brain is large in the pop-out condition, while in the posterior it was larger in the search condition. The phase-phase coupling value is no difference between younger and elderly in the gamma oscillation activity.The previous studies have shown that the anterior in brain is related to the ability to suppress the effect of distractor. Also, the ability will decline with aging. The coupling value in the anterior brain in elderly and search condition may related to the decline in the ability to suppress the effect of distractor in elderly, or that the effect of the distractor cannot be suppressed totally thus it need the participating of the top-up control. The coupling value in gamma band activity showed that there is no difference between younger and elderly. The result showed that the phase-phase coupling in gamma oscillation was unrelated to aging.