A smell you get while passing a place can drag you back to the past and relive your sometimes pleasant and sometimes unpleasant experiences. So how is it that events that have been hidden and lost in the depths of our brains, or even that we have forgotten to have happened, come to light again with a smell? Or why do we remember these memories with our sense of smell, not with our other senses, for example, our most trusted sense, our sense of sight?
The reason is that the sense of smell completed its evolution before the sense of sight, touch and hearing, and therefore has a longer evolutionary history than other senses. In short, the sense of smell began to develop and became specialized long before the other sense organs developed. As a result of the researches, it was found that while there are 4 types of touch and light receptors in humans, there are 1000 receptors for smell. While the inputs we receive with other sense organs are first sent to the thalamus and then to the relevant parts of the brain, the sense of smell goes directly to the olfactory bulb, that is, to the olfactory bulb (region), without passing through the thalamus, that is, it reaches the brain directly and makes us make a direct association. The reason why this association-remembering- is not experienced directly in other sense organs is that the thalamus does not filter the perceived things and bring them to the level of consciousness that they deem unnecessary, and this mental filtering is not possible for the sense of smell.
The olfactory bulb and the hippocampus responsible for memory are located side by side in the brain. ( It would be useful to open a short parenthesis here. The hippocampus is located in the limbic system. The limbic system is a system that includes the brain regions called the hypothalamus, hippocampus, thalamus and amygdala. Here, only the hippocampus and amygdala are of interest to us. ) In previous studies, it was thought that the olfactory center was located in the hippocampus because the olfactory bulb and the hippocampus, which is responsible for our memory, were located side by side in the brain, but later studies proved that this information was not correct. The olfactory region is thought to have its own special memory area, although its accuracy has not been proven. He also revealed that memories recalled through the sense of smell are clearer, more intense, and more emotional.
As a result, the reason why the smells we take take us to memories that we do not even remember their existence, and the emotions such as happiness or unhappiness we feel at those moments is that the sense of smell is transmitted directly to the depths of the brain and, due to its location, awakens the limbic system and activates our memory and emotions.
