Evaluation of Emotional Changes During Earthquake Video Watching: A Wearable NIRS Study

Sudden occurrences of disasters often agitate people emotionally and make their planned evacuation activities difficult. However, the biological responses to natural disaster situations have not been investigated. This study aimed to: 1) discover the difference in emotional responses between earthquake video-watching and neutral video-watching conditions, and 2) investigate the relationship between emotional responses during watching an earthquake video and subjective emotion assessment/individual anxiety traits. Healthy young adults (n = 12) watched earthquake and neutral videos, and we measured biological signals and performed emotional assessment. We measured biological signals, such as pulse rate and cerebral blood flow in the dorsolateral prefrontal cortex, using a wearable two-channel near-infrared spectroscopy (NIRS) unit. Autonomic nerve indexes (sympathetic and parasympathetic indexes) were calculated from the NIRS data. Subjective emotion assessment was made using the Self-Assessment Manikin. The State-Trait Anxiety Inventory Questionnaire was also performed. We found that sympathetic nerve activity was significantly lower in the earthquake video-watching condition than during the neutral one. Biological indicators inferred both subjective emotion assessment during watching the earthquake video and individual anxiety traits. Autonomic indices based on 2-channel NIRS data may be able to estimate emotional responses to different stimuli.