In daily life, people have tried to understand emotions from gestures, mimics, or facial expressions however, some of them can betray no emotion to be strong. However, the more you work your emotion in a scientific manner, the more you will feel better and calm down. For instance, while you are surfing on social media, you see the story of your friends on vacation. So, you can feel raw about this story but you may want to keep a straight face around the people (Edwards, V. V.,2020). But then, the chemistry of the atmosphere blows the whistle on emotions of the people in which the system is called volatile compound biosensors (VOC sensors).
Emotion is produced by the interaction of the limbic system, the autonomous nerve system, and the reticular activating system. The limbic system has many components that control both emotion and memory. Specifically, the hypothalamus plays a vital role in the activation of the sympathetic nervous system that regulates any emotional reactions. Also, the amygdala plays role in emotional information processing and transmitting onto the cortical structure. In addition to these systems, chemicals are an important part of the mood of the human. Information is transmitted through the neurons as an electrically, electric arc is done by these chemicals called neurotransmitters (dopamine, oxytocin, gaba (gamma-aminobutyric acid), acetylcholine).
Volatile organic compounds are the compounds that the human body is emitted into the air by breath or through the skin (Nature). Especially, human breath is a volatile organic compound cocktail that has more than 250 different VOCs in the mixture. Major compounds found in the human breath are acetone (1.2-900 ppb), ethanol (13-1000 ppb), methanol (160-2000 ppb), isoprene (12-580 ppb) and in addition to them, ammonia and minor compounds such as pentane, alcohols, ketones, and aldehydes are found in the exhaled air (ACS).
There are so many choices found for the detection of the chemicals. The main challenge of the detection is VOC capturing. In nature, the atmosphere is the main medium to transfer the chemicals for not only humans but also animals, plants, bacteria as well. Such chemicals may act as a signal which is transmitting from one species to another one. In the case of human beings, these compounds might reflect the emotion if they can be read appropriately. To understand of the VOC secrets, so many new devices are studying in the world. Some of them are mimicked the human dynamic responses against the external stimulus, some of the sensors are created by using like dissolves like principle, some of the devices are customizable for each and every person to grab human VOCs (ACS).
After VOCs are confined to the device, the second challenge begins which is data reading in an appropriate way. By using gas chromatography-mass spectroscopy, optical, chemi-resistive, and electrochemical approaches; absorb VOCs are analyzed.
An emotion is a psychological condition that causes chemical changes in the human body with external influences. The level of emitted VOC and CO2 in a closed particular area shows that the emotional states of the people are changed due to doing actions in that area. For instance, when cinemagoers go to the cinema, VOC and CO2 level increase after a while, and then the detector can capture most of the organic compounds. Composition of the exhaled air change based on the genre of the film, age, and culture of the audience (Williams et.al.,2016).
According to some studies, CO2 emitting level was measured by a sensor in the cinema hall. The audience was divided into several groups based on age (0, 6, 12, and 16) and the film frame was used as external stimuli (incidence of violent, antisocial behavior, drug usage, bad language) among these age groups. Based on results, isoprene could be used for classification for a variety of film genres and age groups (PLoS ONE).
So, this situation makes the sentiment analysis valuable for various industries such as cinema, advertisement, and also health. Thanks to artificial intelligence technology, interpretations of the unconscious movement of the people are analyzed via this technology.
Edwards, V. V. (2020, April 22). The Ultimate List of Emotions and How to Control Your Emotions. Retrieved from https://www.scienceofpeople.com/emotions-list/
Boundless. (n.d.). Boundless Psychology. Retrieved from https://courses.lumenlearning.com/boundless-psychology/chapter/biology-of-emotion/
Qu, C., Wang, S., Liu, L., Bai, Y., Sun, F., Hao, M., et al. (2019). Bioinspired Flexible Volatile Organic Compounds Sensor Based on Dynamic Surface Wrinkling with Dual-Signal Response. Small, 1-8.
Jalal, A., Alam, F., RoyChoudhury, S., Umasankar, Y., Pala, N., & Bhansali, S. (2018). Prospects and challenges of volatile organic compound (VOC) sensors in human healthcare. ACS Sens., 1-21.
Williams, J., Stönner, C., Wicker, J. et al. Cinema audiences reproducibly vary the chemical composition of air during films, by broadcasting scene specific emissions on breath. Sci Rep 6, 25464 (2016). https://doi.org/10.1038/srep25464
Sto¨nner C, Edtbauer A, Derstroff B, Bourtsoukidis E, Klu¨pfel T, Wicker J, et al. (2018) Proof of concept study: Testing human volatile organic compounds as tools for age classification of films. PLoS ONE 13(10): e0203044. https://doi.org/10.1371/journal.pone.0203044
2. Figurun: https://doi.org/10.1371/journal.pone.0203044.t003