Technology opens up the world of perception: What happens when the senses are "digitalized"?

According to Buddhist theory, people have six senses: eyes, ears, nose, tongue, body, and mind. These six senses are also the channels through which we, the mortals, perceive the world.

The tongue is the key to supporting the survival of our body. The comfort that food brings us is also the reward for everyone's hard work.

However, the reality seems to tell us that it is too difficult to strike a balance between delicious food and a healthy body, and the result of enjoying delicious food always means giving up some of our health.

So in the field of diet, can technology play its strengths and allow us to have both delicious food and good health? Recently, a study in Japan solved this problem that has troubled us.

Salt Control Magic Chopsticks

Professor Homei Miyashita from Meiji University in Japan has developed a pair of electric chopsticks that can help people taste salty food without adding extra salt.

We may have learned through TV and the Internet that the Japanese diet is mainly light, but in fact, according to the "National Health and Nutrition Survey Report (2020)" released by the Ministry of Health, Labor and Welfare of Japan, the daily salt intake of Japanese adults is twice the amount recommended by the World Health Organization, which recommends a maximum of 5 grams of salt per person per day. If you want to change the salt intake in your diet, you need to change your lifestyle habits, which also means that salt control is likely to become a slogan. This is also an important reason why Japanese scientists are committed to using technology to change taste perception.

This research is the result of a joint study by Professor Yoshiaki Miyashita and beverage manufacturer Kirin Holdings Co. The principle is to stimulate the taste system by using very weak electric currents, changing the human taste perception of food without affecting the normal function of the human body.

The experiment selected 36 men and women aged 40-65 years old, and asked the subjects to use electronic chopsticks to taste samples that simulated ordinary food (containing 0.80% salt) and samples that simulated low-salt food (containing 0.56% salt), as well as taste reduced-sodium miso soup. When electrical stimulation was applied, the subjects' perception of saltiness for samples that simulated low-sodium food was the same as that for samples that simulated ordinary food. In the experiment with reduced-sodium miso soup, the subjects reported that the richness and overall taste of the miso soup were improved after using electrical stimulation.

This shows that when the subjects used electronic chopsticks to taste food with 30% less salt, their perception of saltiness was comparable to that of ordinary food. In other words, when eating food with 30% less salt, chopsticks equipped with this technology can improve the perception of saltiness by 1.5 times.

Many people are concerned about whether these chopsticks with electric current have any health effects on the human body. Research technicians said that the weak current on the electronic chopsticks is controlled by a microcomputer and will not damage the taste function.

Salt is one of the most important ingredients in the diet. If you don't pay attention to excessive intake, it will easily cause diseases such as high blood pressure. By using weak current technology to reduce the salt intake of traditional diets, we can follow the low-sodium and low-salt diet advocated by health without affecting normal eating habits. It is also a great blessing for Asians who like soups and watery diets.

Whether for healthy people or people with high blood pressure, electronic chopsticks are a good dining companion, allowing us to stay away from diseases while enjoying food normally. As for when these chopsticks will be sold, Professor Yoshiaki Miyashita and Kirinsha said they are improving the prototype of chopsticks and strive to commercialize them as soon as next year.

Scientists are still exploring the technology of taste perception, and research related to brain-computer interfaces is gradually digitizing the difficult-to-quantify sense of taste.

Identifying taste perception

In some taste test experiments, the traditional method has always been through questionnaires or sensory panel analysis, but this test method is output after each of our individual brain nerves are processed, so the output of the results may not be so accurate for some experiments with more stringent requirements. Scientists want to find out what our first reaction taste perception is in these taste tests.

Brain-computer interface technology is trying to accurately identify brain signals of various tastes, and the principle premise of the research is that the perception of taste will be reflected in our brain in the form of neural signals.

When our tongue senses taste stimulation, the taste signal is transmitted to the taste cortex of the insula through the thalamus. At the same time, the brain's reward system receives the signal of wanting to eat from the frontal cortex. These signal transmission processes communicate with other neurons in the form of specific electrical pulses. The signals generated by this process can be detected in the form of cerebral blood flow, blood oxygen and EEG.

The rapid development of biocomputing technology has made it possible for neural activity detection technology to collect accurate spatiotemporal information of brain activity areas. Electroencephalogram (EEG), magnetoencephalogram (MEG), functional magnetic resonance imaging (fMRI) and other technologies can detect neural activity in the brain. The brain area responsible for specific food stimuli (sour, sweet, bitter, salty, fresh) is stable and unchanging, so the use of brain-computer interface system can decode taste information from neural signals.

The researchers placed various types of electrodes at specific locations on the subjects' heads, ears, etc., collected various signals in different frequency bands in real time, and used machine learning and other technologies to identify the signal characteristics under these different taste stimuli.

During the recognition process, the signal intensity obtained by most EEG studies shows a decreasing pattern from salty to sweet (salty> sour> bitter> sweet). Therefore, these intensity differences can be used to study the discrimination of specific tastes.

The study found that consumers' tastes and choice preferences can be predicted by changes in brain signals. Researchers believe that the emotional component in food preferences will also affect the taste experience. The EEG signals induced by foods with the best taste experience mean a high level of happiness.

We can find that in different scientific studies, taste has become closer to us than before, whether it is using microcurrent technology to deceive the brain for health, or using brain-computer interfaces to identify different taste electrical signals one by one, taste has gradually changed from a vague experience to clear information. In-depth research on this sensory tool will also guide our application in the fields of diet, medicine, manufacturing, etc.

When the senses go digital

When we taste food, the perception of taste will cause a series of physiological changes in the body, which can be recognized by EEG signals. Our facial expressions and heart rates may also change. By classifying and analyzing these recognition results, we can obtain potential reactions, which can be used as a tool to understand people's acceptance of the taste of new foods. It can also enhance the research and development, innovation and sales promotion of new foods.

For some special groups, such as infants and people with aphasia, taste recognition through brain-computer interfaces can also be used to test specific foods that are suitable for these groups, thereby improving their quality of life.

Of course, the digitization of taste can also be applied in the field of medical health. Some patients who lose their sense of taste will become nervous, painful and distressed due to changes in taste, which will lead to a decrease in appetite and may even cause anorexia nervosa, seriously affecting the quality of life. Patients with sequelae of the new crown and chemotherapy for cancer will face these painful moments. However, in the future, the loss of taste can be accurately stimulated by technical means to obtain the taste of food in the relevant brain areas, reduce the psychological pressure and health burden of patients, and the clinical application of taste stimulation therapy will also expand in the future.

In the field of digital entertainment, the digitization of senses can also make the experience of the virtual world more colorful. The digital application of taste is also very promising in the field of the metaverse. Previously, researchers from the National University of Singapore developed a sensor device that can control taste. By configuring different stimuli: current, frequency and temperature, it can simulate sour, salty, bitter, spicy tastes, and even mint flavors by using thermal stimulation.

If these stimuli are combined, the taste buds can be deceived, making the brain think that it is experiencing the fusion of food. In the digital world of the metaverse, the sensory experience will become richer and richer. A simple taste sensor can allow us to taste all kinds of delicacies from different cultures and regions in the virtual world.

Taste is one of the most indispensable feelings of our senses. Among the five basic tastes, sweet and salty tastes make people feel that food contains nutrition, while sodium in salt can arouse desire and appetite, and sour and bitter tastes make people feel that food contains acidity and toxicity, thus causing a taste reaction of contempt and disgust. It is these rich tastes that make us feel the beauty of food and nutrition, which is a gift from nature to us.

However, some unfortunate people will lose their sense of taste for various reasons. We have also seen some patients who have temporarily lost their sense of taste due to the COVID-19 pandemic sharing on social media. The failure of taste makes them painful and depressed. All food has lost its taste and even tastes strange and smelly, which makes them even want to commit suicide. There is no fun in life at all. There was no solution to this kind of individual sensory experience before. But now various in-depth studies on taste allow technology to deepen and amplify individual sensory feelings and solve the troubles of some suffering people.

Our senses have always been dominated by various organs such as eyes, ears, nose, tongue, body, and mind. The leap in technology allows the senses of eyes, ears, nose, tongue, and body to be intervened, cured, and enriched, and the various experiences of the digital world and the physical world are intertwined and overlapped. Maybe in the future, although the virtual world has no sense of reality, the experience from the sensory level will be enriched and enriched, full of truth and falsehood, and full of fun. The field of philosophy may also be more exciting because of these changes in senses, and the propositions and discussions about reality and illusion will be more exciting. That day may also be a historical moment when the boundary between the real world and the virtual world is blurred.