What comes to your mind when you hear the phrase "involuntary memory"? This does not apply to everyday experience and recent life events. The brain stores information in the backyard of consciousness, and certain signals refresh events that happened to you a long time ago. For the first time this concept was introduced at the beginning of the twentieth century by the French writer Marcel Proust. On the pages of the first volume of the novel "In Search of Lost Time" a character appears who drinks tea with cookies, the aroma of which takes him to a carefree childhood. At one point, a vivid picture of the past appears in front of the hero. He remembers the places where he was, his surroundings and other details. So the delicate aroma of baking helped to restore the events of many years ago. Psychologists now call sensory experiences that induce strong autobiographical memory the "Proust effect."
Smell is closely related to autobiographical memory
Some scientific studies show that memories are most emotional when triggered by scent. Compared to other senses, the sense of smell is the champion when it comes to recreating events stored in autobiographical memory. Neither sounds nor visuals can do what smells can do. Of course, this statement is true for both good and bad events. In our life, not everything can be associated with vanilla cookies. A new study in psychology, published in the journal Frontiers, described one potential use of the sense of smell. Scientists claim that people can identify strangers by their body odor. This fact did not go unnoticed by law enforcement agencies, who are ready to accept testimony,investigating complex and intricate criminal cases.
Why is the sense of smell stronger when it comes to strangers?
The smells of the bodies of strangers are perceived by the human nose differently. For example, the familiar scent of friends or family will be less intense than that of a suspicious stranger. Our nose also remembers the places where we go. For example, cinemas do not only smell like popcorn and human emotions. But, it seems, the places where some strange and dangerous events took place are most clearly engraved in the memory. This is the smell of the entrance to the barracks on the outskirts of the city. Scientists decided to find out if the olfactory capabilities of crime witnesses can be equated with the capabilities of sniffer dogs. In fact, the human nose is much less finely organized than the dog's. The yard dog's sense of smell is supported by 300 million receptors. The human nose has a more modest performance: only 5 million olfactory receptors.
Promotional video:
Emotional events remain in our minds for a long time
If we consider especially emotional events, then they have a special “code”. And only the sense of smell can unlock memories from the past. Wendy Suzuki, a psychologist at New York University, describes this phenomenon in terms of the structure of the brain: “The olfactory system has connections with two key regions of the temporal lobe - the hippocampus and amygdala. The former is critical for the formation of new long-term memories, the latter is indispensable for processing emotions.
Unlike all other senses (vision, touch and hearing), the olfactory system does not require multiple connecting structures - synapses. The aroma penetrates the hippocampus and tonsil in a direct way. This is why smell has the ability to form long-term memories associated with a particular time or place (the hippocampus is responsible for this). That is why a person, plunging into the surging memories, thanks to the amygdala, has the opportunity to feel a deep emotional resonance."
What is the strongest emotional experience a person has?
What could be more emotional than seeing a bloody crime unfold in front of an observer? To confirm these guesses, New York researchers conducted an experiment in two parts. First, 73 students were asked to watch violent videos. In parallel, the study participants sniffed a piece of cloth containing a stranger's body odor. A separate group of volunteers was responsible for the formation of "evidence", wearing special pads under the T-shirts in the armpit area. The participants then sniffed samples in collections of three, five or eight fragrances. From all the materials presented, people should have recognized the smell they first met, even when watching the video. It was sort of an olfactory stunt double for the typical police lineup.
Results of the first part of the experiment
As a result, the participants who received a collection of three fragrances were the closest to the truth (coincidence in 96 percent of cases). The five applicants caused much more difficulty: only 56 percent of the time people guessed the original sample. The indicators worsened a little more when it came to eight fragrances. In this case, the volunteers recognized only 46 percent of the samples. Although here the indicators have decreased only slightly. There were also tests for random guesses, which, however, turned out to be a complete failure. Note that there was 15 minutes between the first and second sessions of the first part.
Weekly interval
In real life, such a short period of time does not solve much. If a person becomes a witness to a crime, he is unlikely to have time to get to the police station so quickly to testify. Sometimes witnesses hesitate for a long time to confess, fearing revenge on the part of criminal groups, sometimes they are in deep shock. And only when the policemen begin their painstaking work, the witness refreshes those unpleasant events in his memory. Therefore, the authors of the study provided for the second part of the experiment, where one week was kept between sniffing sessions. The results were not so encouraging. The researchers acknowledged that the longer interval between sessions was confusing to the participants. And now the choice was wrong in most cases.
conclusions
If police officers want to cooperate with witnesses on odor samples, this should only be done in hot pursuit. In addition, the human brain cannot identify a fragrance that has been compromised by chemical components (deodorants, washing powder, perfume). Smell can be another way people can refresh their memory. At the same time, body scent mixes so easily with artificial ingredients that it can easily mislead a person.