Sometimes when we hear a familiar smell, it is quite familiar to remind us of certain memories, sometimes it takes us back to our childhood memories. Thus, we are often dragged into a series of memories. Fragrances remind us exactly where we feel, the people who were there at that time, and even what we are feeling at that moment. So, what’s going on in our brains at that moment, and what are we thinking about? American neurologists, how we remember a familiar smell and the moment when the smell is associated; To elaborate further, they conducted a study on which mechanism of the brain provides this. It is very difficult to express the smells. In cases where we cannot fully define it, we can also associate the smell with any object; For example, “granny’s house smell” is a good example of this. From this moment on, the things in that house and the specific moments experienced come to life in the mind by forming a whole. So what mechanism of the brain allows the sense of a smell that we already know to be reminiscent of associated memories? According to a study published April 16 in the journal Nature, this mechanism occurs via brain waves between the two regions; one of them is the entorhinal cortex, also known as the secondary olfactory region, which is essential for storing odor and comparing it to the odor in memory at the next encounter; another is the zone of the brain called the hippocampus (brain prominence), which has a very important place in memory and reminds us of past events. The hippocampus is located right next to the olfactory bulb. This is accepted as a meaningful inference in associating smell with memories.
The smell of my grandmother’s house The toy cabinet at my grandmother’s house had a distinctive smell. It’s a scent I can’t describe. Now once in a while I smell that smell in my nose. Some memories come to life with the smell, memories that I thought were lost; my grandmother, my going to her house, my playing with the toys there… So, how is it that smells can bring back memories that we thought we had forgotten? In the Tom Stafford article published in BBC Turkish; “Neurology is a bit like a detective story; It is necessary to look for clues to find the cause” and examines the available information on this subject before examining the clues. Complex Senses The sense of smell is the oldest; It goes back to the primitive senses even bacteria possess, which evolved to sense chemicals in the air and water. Before the sense of sight, hearing and even touch, the sense of smell developed so that living things could react to chemicals around them. Seeing is possible with the four light sensors in the human eye. Cells that act as receivers here convert light into electrochemical signals in language the brain can understand. The sense of touch is dependent on at least four types of pressure, as well as various receptors that detect heat, cold, and pain. But these are overshadowed by the sense of smell. Because there are more than 1000 receptors in humans that enable them to smell. These are renewed as we live and change according to the smells we are used to. This complex structure allows us to distinguish many different scents from one another. However, we cannot find a name for all the scents we can distinguish. Perhaps our least talked about sense is smell. We can describe well how something looks or sounds, but when it comes to smell we try to express it in terms of what we connect with; for example, like a flower, like a wet dog, etc. we define as. In other words, we express the smell with the object that creates that smell: like “coconut”, “fresh bread”. Memory and Smell After repeating this information, now let’s see what are the important clues? The region of the brain that processes odors and is called the “olfactory bulb” is next to the cerebral cortex (hippocampus). This seahorse-shaped onion is where all the information coming from the cortex is gathered.
Neurologists have found that the hippocampus has an important function in creating memory for new events. People with damage to this part of the brain have difficulty remembering. Although they learn new skills such as cycling and new information such as people’s names, they cannot form a memory about them. This intermittent “episodic memory” is the very memory involved when remembering our visit to my grandmother’s house. Since the olfactory bulb, that is, the place of smell in the brain, is next to the hippocampus, which is the source of this type of memory, we can say that smells evoke some memories. Diving Deep But as powerful as this tip is, it’s indirect and circumstantial. Therefore, it is necessary to offer a second tip. Among the senses, the unique feature of smell is that it goes directly to the depths of the brain. Whereas, for example, the senses of sight and hearing begin in the eye and ear, that is, in the relevant organs, and before they pass to other parts of the brain, they pass to the thalamus, which functions as a transfer center, that is, to the middle part of the midbrain. The sense of smell goes directly to the olfactory bulb without passing through the thalamus. We do not know how the pause in the thalamus functions for the other senses; but we can say that the signals generated by others are “farther” from the processing center in the brain. Could the difficulty of putting the scents into words be due to this? Or could it trigger the resurgence of deep-seated memories? Research shows that expressing events and facts in words is beneficial for memory; but it also leads to a decrease in feelings about the subject. As we talk about our memories, we begin to remember the event and the experience it created. Going back to my grandmother’s toy closet… The olfactory receptors of my child’s nose have picked up the scent of the closet. This smell, which I can’t find a name for, moves directly to my brain and settles next to the area that encodes experiences. It was there, mixed with other memories of the closet, never put into words, that were consciously hard to remember but still imprinted in my memory. Years later, when I smell that scent today, those childhood days come back.