Why Smells Are Memorable?
Scent Memory
The nose is just one of our five senses and perhaps the most intriguing. The sense of smell and memory have remarkable and surprisingly interesting commonalities.
When you walk down the street, the scent of perfume can trap you in memories and even revive a previous event. When you enter an environment, a scent can remind you of an event you thought you had forgotten. So how is it that all these memories that we think we have forgotten can be revived with a scent?
The sense of smell is the oldest known sense. It is one of the most primitive senses that evolved in single-celled organisms to react to chemicals in the environment before sight, hearing and even touch. The sense of smell, therefore, has the longest evolutionary history and corresponds to one of the oldest regions of the human brain. Humans have at least 1000 different types of receptors for smell. By comparison, we have 4 types of light receptors and 4 types of touch receptors. This helps explain why the sense of smell evolved earlier.
We can smell odours around us, everywhere we live or go, that we’ve never smelled before. But the difficult thing is to name them. If you’ve noticed, we can never fully describe a smell. We usually try to describe odours in terms of the object that creates the smell. For example, “It smells like flowers” or “It smells like hot bread”.
How İs Smell Processed İn The Brain?
The “olfactory bulb” is the area of the brain responsible for processing odours (This area is called the olfactory bulb and is located next to the hippocampus. In this seahorse-shaped region, all the information from the cerebral cortex is collected. Neurologists call it the olfactory bulb. The role of the hippocampus in creating memories for new events.
People with damage to this area of the brain may have difficulty remembering. They often cannot form a memory for newly learned knowledge and skills, such as people’s names, even if they have just learned them. This is called “episodic memory” and is the same memory that comes to life when we walk down the street and smell a familiar perfume! The association between smells and memories is much stronger because the olfactory bulb is located next to this memory.
This unique feature of the sense of smell compared to the other senses lies in the fact that it reaches directly deep into the brain. This is because all other senses first visit a relay centre called the thalamus and are then transmitted to the required brain region. The sense of smell, on the other hand, goes directly to the olfactory bulb without passing through the thalamus. It is not yet clear why the other senses pause in the thalamus or why the sense of smell reaches the olfactory bulb directly, but we can say that the signals produced by the other senses are farther from the processing centre in the brain than the sense of smell.
To summarize, this is why odors trigger memories: The olfactory bulb is physically very closely associated with memory centers such as the amygdala and hippocampus. It is also directly connected to some higher-level cognitive regions and can store some memories on itself. All this explains why a memory is triggered immediately when we smell something.
