Evaluation of emotional influence on EEG activity in the frontal lobes

The electroencephalographic (EEG) activity is analyzed here to detect alpha rhythms asymmetry related to induced depression; EEG signals were acquired from the frontal lobes. Seven young subjects, students of similar age, voluntarily participated in the experiment. The initial emotional state of the subjects was assessed by three independent questionnaires, designed for psychological evaluation of depression and the results were compared. Several sequences of recordings were taken afterward (base, induced happiness, and induced sadness). The left dominant alpha-asymmetry (LDAA) index was calculated for each EEG recording. The outputs were analyzed and compared with similar assessments presented in the scientific literature, leading to similar conclusions, i.e. stimulated happiness lowers the LDAA index and stimulated sadness raises the LDAA index. The results also suggested that the repetition of the process tends to lower personal index values from one session to another.