Brain-Computer Interface for Multi-Parameter Mental State Evaluation

With the increasing development of wireless devices in the field of Brain-Computer Interface (BCI), it is very important to evaluate the mental state of users using BCI products in daily life. There have been many studies on mental states in the past, such as studies related to concentration, fatigue, or stress, but most of them are studies of a single mental state. We proposed a multi-mental state indicator based on EEG signals which can real-time reflect the subject's mental states, including fatigue, attention, stress, and the left and right brain activity changes. For validating the effectiveness of the proposed evaluation system, we also designed a complex mixed-object search experiment. Results showed that attention levels while performing the objective searching task were significantly higher than during rest periods. Contrast, the fatigue level while rest periods gradually increased and steady by the third rest period. Stress levels, similar to attention levels, decreased as the experiment progressed. The proposed indicator is applicable to potential BCI applications for evaluating the subject's mental state change in real-time.