MODEL OF MOOD DYNAMICS BY INVOLVING HORMONAL INFLUENCES

• Main Author: Tirandika, Intan
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/65270
• Institution: Institut Teknologi Bandung

The phenomenon of mood changes occurs every day. Significant changes in feelings that occur at certain times can be caused by limited social interaction due to COVID-19. But in fact, many women naturally experience this phenomenon every month. This phenomenon is commonly known as Premenstrual Syndrome (PMS), which are physical and emotional symptoms experienced by women before their menstrual period. The purpose of this final project is to see if there is an effect of menstruation on women's feelings. Beginning with a feeling survey for 28 days, a model of changes in feelings will be constructed in one menstrual cycle. The model constructed refers to a spring mass system with a vertical motion direction. The model parameters involve menstrual hormons such as estrogen and progesterone, as well as one of the happiness hormons, namely serotonin. The model simulation uses the Runge Kutta method of order 4, this is done to see the effect of constant and periodic menstrual hormons on mood swings and mood changes. In addition, the external disturbance is applied in the form of a constant function. In the mood change model for constant and periodic hormone levels, stability was investigated using the Jacobi matrix and phase portraits. Then further built the Lyapunov function for the system. The results of the survei showed that not all of the samples had feelings or moods that worsened before the menstrual period. Based on the simulation results, constant hormone parameters did not show any difference in mood. Meanwhile, the periodic hormone shows that at the beginning of the cycle the sample feels better and in the period before menstruation the feeling gets worse. This is due to the influence of the hormons estrogen and serotonin, which begin to increase in the first period and then decrease at the end of the cycle. External disturbances applied to the model provide variations in mood swings, the difference is more visible when hormone levels are periodic than hormone levels are constant. The eigenvalues of the Jacobi matrix and Lyapunov function state that the ekuilibrium point of the system has stabilized, but the phase portrait shows that the Hopf bifurcation occurs in the system. This means that the system is very sensitive to small changes or variations of parameters.