Subverting cognition: It only takes 1 to 3 seconds! How can humans "smell" things so quickly?

Author: Xu Yahui Duan Yuechu

Human olfactory perception has always been a mysterious area. For a long time, human smell has often been regarded as one of our slowest senses. This is partly because the changes in olfactory perception caused by rapid chemical dynamics are extremely difficult to measure. However, the latest research results have revealed the amazing capabilities of human smell.

According to a groundbreaking paper published in Nature Human Behaviour, humans can distinguish different odors released in a specific order in a single sniff, nearly 10 times faster than previously thought. This discovery completely overturns our previous inherent understanding of the speed of human olfactory perception.

In order to explore the mystery of human smell, researchers have carefully crafted an extremely sophisticated instrument. This instrument has amazing high accuracy and can accurately deliver odors to the human nose in just 18 milliseconds. This technological breakthrough provides a solid foundation for subsequent experimental research.

During the experiment, the researchers invited 229 participants to participate in a series of rigorous experiments. The experiment mainly required the participants to distinguish two different smells in order. These smells are composed of compounds similar to the smell of apples, onions, lemons, and flowers. These smells were presented to the participants in a specific order or in reverse order, and different time intervals were set between the smells under different experimental conditions.

In one of the key experiments, participants were required to distinguish between two odors presented in different orders. Surprisingly, the experimental results showed that participants only needed one sniff, which usually lasted 1-3 seconds, to clearly distinguish between two odors presented in one order and then in reverse order with an interval of only 60 milliseconds. This result fully demonstrates the high sensitivity of human olfaction in temporal resolution.

Moreover, in another equally important experiment, participants were asked to rate the similarity between a mixture of odors and their individual components. The researchers found that when the interval between the delivery of the two odor components was extended to between 100 and 200 milliseconds, participants reported that the mixture smelled more like the first component presented than the later component. This phenomenon clearly shows that the order in which the components of an odor reach the nose plays a crucial role in identifying the characteristics of the odor.

From these experimental results, we can deeply understand that human olfactory perception ability is far beyond our previous imagination. Its fineness in temporal resolution is comparable to the speed at which we perceive color. This means that when processing odor information, our olfactory system can capture the dynamic changes of odor in a very short time in an extremely efficient and accurate way.

This research result is of great significance for our further understanding of the working mechanism of the human olfactory system. It opens a new window for us to explore the mysterious field of olfactory perception more deeply. In the future, we can expect to carry out more research on olfaction on this basis to further reveal the close connection between olfaction and human behavior, emotion and health.

The emergence of this research result has also brought new opportunities and challenges to the development of related fields. For example, in the field of perfume research and development, this discovery may prompt perfumers to pay more attention to the time sequence and interval of the release of different spices to create a more unique and charming aroma combination. In the medical field, the research and treatment of olfactory disorders may also achieve new breakthroughs due to a deeper understanding of the olfactory perception mechanism.

In short, the mysteries of human smell are still waiting for us to explore and discover. This latest research result is just an important milestone on our road of exploration, which inspires us to move forward and uncover more mysteries about human smell.