April 13 is International Kissing Day , commemorating the longest kiss in recorded history, which lasted 58 hours. Its protagonists, the Thai Ekkachai and Laksana Tiranarat , kept their lips glued together for more than two days, obtaining the Guinness world record. Without a doubt, they had to train a lot to win the kissing championship, which is held every year in February to coincide with Valentine’s Day.
Surely the couple from Bangkok will not easily forget that day. Nor do many people forget their first kisses . They do not need to break any records, it is enough that they are the first kisses. There is something special about them that their memory is fixed in the memory of many people.
Everyday experience , from the most innocuous to the most significant, is capable of modifying our brain and changing our behavior, adjusting it to what is most useful and necessary. Experience is thus the source of memory . Although we should better say “of memories”, because there are many kinds of them.
Short -term memory is used to record information for immediate use. He defends himself very well by keeping memories for minutes. To remember things that have happened from a few hours ago to many years ago, we need long-term memory.
Episodic memory , a type of long-term memory, is what allows us to retain our autobiographical experiences in memory, accompanied by information about what was happening in the environment, what we felt and what we thought while living such experiences.
Although memory is a very complex process, and memories are stored in neural networks located throughout the association cortex of the brain, there are areas that are more involved in memory formation than others.
Speaking of our first kisses, the hippocampus takes pride of place. It is a double brain structure (there is a hippocampus in each hemisphere ), which is located in the temporal lobe . So called because its shape is reminiscent of seahorses, it is essential for the formation of “what-where-when” memories, characteristic of episodic memory , the type of memory that allows us to recall something as beautiful as our first kiss. .
Not all autobiographical memories are recorded equally well. Why is the first kiss usually between those who do? We have to look for the answer in the emotional intensity with which we experience the events.
The memory of the first kiss, as an episodic memory , is constructed from the association in space and time of the elements, objects and events that were within our reach at that special moment: things like where we were sitting, the our partner’s clothes, the touch of their skin, the smell of their perfume, the taste of their lips…, and also if it was day or night, if a song was playing or the crickets were singing, for example.
The external stimuli that surround the first kiss are captured by the sensory organs , and are encoded in our brain through biochemical changes and structural modifications in various groups of neurons, populations of cells that constitute a memory trace, and that will be activated again each time Let’s remember the kiss.
Said coding process can be seen reinforced with the high involvement of the amygdala , a brain structure made up of several anatomical nuclei that is related to the processing of emotions. The nervousness, the expectations, the pleasure, the fear of the unknown of the first kiss, cause a torrent of substances and hormones that intensify the experience, contributing to its better consolidation and reactivation in memory.
The same happens with emotionally negative experiences : they will tend to be remembered more than less emotionally charged experiences. Until a certain point. If emotions are extreme, as in the case of sexual assault, memory consolidation can be severely affected, leading to amnesia.
Thus, it makes sense that the first kiss is recorded as important for the individual, precisely because of the intensity with which it has been experienced and then evoked. In some people it becomes a “ privileged memory ”, which can remain with them for a lifetime.
However, it’s okay if you don’t remember your first kiss, not everyone does. Precisely because episodic memory depends on the emotional state of the individual, it is also sensitive to forgetting and interference. This is why you may have the taste of your first kiss recorded, but you do not remember what day it was, where the magic occurred or what clothes you were wearing. In the process of remembering , we tend to fill in the gaps with false memories . Something interesting if that first time was a disaster and we want to “decorate” it.
The learning that our first kiss gives us is a neurobiological process that will influence how we will react to subsequent kisses. Once we have acquired this information, we will be able to use it in future romantic encounters, although other kisses may never be so special to us.
References:
Bradley, M. M. 2014. Emotional memory: A dimensional analysis. In Emotions (pp. 111-148). Psychology Press.
Jimenez, J.C. et al. 2020. Contextual fear memory retrieval by correlated ensembles of ventral CA1 neurons. Nat Commun 11, 3492. DOI: 10.1038/s41467-020-17270-w
LaBar, K. S. et al. 2006. Cognitive neuroscience of emotional memory. Nature Reviews Neuroscience, 7(1), 54-64.
Lefkowitz, E. S. 2018. Never been kissed: Correlates of lifetime kissing status in u.S. University students. Archives of Sexual Behavior. DOI:10.1007/s10508-018-1166-y
Sugar, J. et al. 2019. Episodic memory: Neuronal codes for what, where, and when. Hippocampus, 29(12), 1190-1205.
