Proust's madeleine effect: what it is, characteristics and causes

Surely on more than one occasion you have smelled a smell that was somehow familiar to you and a very specific memory has automatically come to mind.

How is it possible? Thanks to Proust's madeleine effect, a phenomenon that we are going to delve into below so that you know the neurological explanation for it.

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What is Proust's madeleine effect?

Proust's madeleine effect is a brain association that we make automatically when we perceive a certain sensation through our senses, generally through the sense of smell, which immediately evokes a past event in us, without any conscious process involved, that is, involuntarily.

The most incredible thing is that this memory can be inactive for years and even decades, buried in the depths of our networks. neurons, and we could perfectly believe that we had completely forgotten it until this unexpected recovery occurs automatic of the same.

The expression “Proust's Magdalene effect” as such comes from the author of the same name, Marcel Proust, who published his work in 1913.

Along Swann's path. Specifically in the first of its volumes, called In Search of Lost Time, which begins with the protagonist preparing to taste a freshly baked cupcake, and When he decides to bathe it in the glass of hot tea and puts it in his mouth, the sensations perceived transport him directly to the memories of his earliest childhood.. In fact, the novel is made up of more than 3,000 pages in which the events that the protagonist remembers as a result of this situation are narrated.

Therefore, the origin of this expression would be purely literary, but after more than 100 years of history, has taken root in both science and popular culture, so it is relatively easy for us to find it in neurology studies or in marketing manuals, as well as in many other areas. Other terms that we can find are Proustian effect or Proust phenomenon, but all of them refer to the same phenomenon, interchangeably.

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Biological bases of this memory phenomenon

We already know what Proust's madeleine effect consists of. Now we are going to see what are the causes at a neurological level for us to experience something as incredible as the Automatic unlocking of a forgotten memory, simply with the power of a smell, a taste or another sensation perceived.

It seems that the part of the brain responsible for this issue would be the limbic system., since in this region the meeting of various structures occurs, with very different functions, but that at the same time seemingly can converge and make the most surprising associations between emotions, memories and perceptions.

Let's look at some of these brain sectors in more detail to better understand how Proust's madeleine effect is generated.

1. Thalamus

The first structure that we find within the limbic system would be the thalamus, which in itself It already has an important collection of functions, which will be vital to study the phenomenon that we are dealing with. occupies And the thalamus processes the information received by the senses, before being sent to the corresponding brain regions that finish integrating this data.

But not only that, but it also participates in processes related to memory and emotions, so it would already be giving us a lot of information. about a key place in the brain where very different functions take place but that can somehow be associated by neural networks shared.

2. hypothalamus

Another of the key brain structures in Proust's Magdalene effect is the hypothalamus, a well-known region of the brain where an infinite number of processes take place, but the ones that interest us in this case are those related to emotions. The hypothalamus would have control over emotional expression at a physiological level.

3. Hippocampus

Also in the limbic system we will find the hippocampus, an area of ​​the brain vitally important for creating new memories, in addition to other functions that are equally important but that are not relevant to explain Proust's madeleine effect.

4. Amygdala

Finally we would find the amygdala, another of the brain regions that share responsibility in this phenomenon, in this case because some of its functions are those intended to manage the emotionality of our reactions, also helping to generate memories impregnated with a specific mood or emotion.

The power of smell

It is worth stopping for a moment to look in depth at the characteristics of the sense of smell, the most powerful when it comes to triggering Proust's madeleine effect in us. And, we have already seen that smell, memory and emotions share certain neural circuits in our brain.

It must be taken into account that The human being is capable of remembering up to 10,000 different smells. In fact, we retain in our memory 35% of the information that comes to us through smell, and only 5% of what we capture. through vision, which is still a huge amount of data, since it is the way through which most stimuli from our environment We received.

These characteristics make smell a powerful trigger of memories, since many of those that remain recorded in our memory are associated with the context of the situation experienced at that moment, so that recapturing a certain aroma will make us mentally travel back to that pleasant situation that marked the first time we registered the characteristics of a certain smell in our brain.

But be careful, because this mechanism does not understand positive and negative stimuli, and just like the smell of, for example, a certain infusion, can transport us to a pleasant place and make us relive a magnificent summer, the opposite may also happen and instead bring us back to in our minds a certain event that was unpleasant to us at the time it occurred and that we had also completely forgotten, or at least that's what we believed.

It is also worth making special mention of the sense of taste, since it usually works in tandem with the sense of smell when it comes to food and drinks.. And it is difficult to separate the sensations that we perceive through the nose and through the mouth when we are tasting a succulent stew, an intense coffee, etc.

Practical applications

In some types of psychological therapy such as EMDR, based on the reprocessing of events traumatic, you can resort to techniques that, although they do not exactly use the cupcake effect of Proust, They use a strategy whose mechanism is very similar in its foundation to help patients.

In this case, what the therapist who is treating the trauma would do is ask the subject to think of a smell that is pleasant to them. for a specific reason (or, if circumstances allow, actually smell that stimulus, for example a perfume or a food certain).

This way, the neural networks that had previously associated that stimulus with certain people, places or moments that are positive for the subject, would bring said memory to the person's mind positive, which would reduce their physiological activation and facilitate the reprocessing of the traumatic event experienced and that is being treated in the consultation.

Smell and memory

But the relationship between the sense of smell and our ability to generate and retrieve memories goes far beyond what we have seen with Proust's madeleine effect. The relationship is so close that many neurological studies investigate the correlation between dementia and loss of smell..

In fact, for one of the most serious neurodegenerative diseases, such as Alzheimer's, one of the indicators used to diagnose whether the person is at the beginning of this disorder would be precisely the problems in capturing odors, and the loss of smell is associated with dementia, by sharing, as we have already seen, brain structures that in this case would be damaged and cause consequences in both capabilities.

Specifically, the critical point of the brain that, when damaged, causes this type of alterations would be the circuit that connects the hippocampus, a structure that we have already seen, with the anterior olfactory nucleus, which in turn is part of the olfactory bulb, located in the forebrain.

For all this we must be aware of the power that the sense of smell has, not only for such curious phenomena as the effect Magdalena by Proust, but for being a valuable indicator that, in its absence, can set off alarms about a possible alteration of the memory.

Bibliographic references:

• Rodríguez-Gil, G. (2004). The powerful sense of smell. California Deaf-Blind Services.
• Miranda, M.I. (2011). The taste of memories: formation of gustatory memory. Mexico. DGTIC University Repository.
• Bonadeo, M.J. (2005). Odotype: Natural History of Smell and its function in brand identity. Buenos Aires. Austral University.
• Aqrabawi, A.J., Kim, J.C. (2018). Hippocampal projections to the anterior olfactory nucleus differentially convey spatiotemporal information during episodic odor memory. Nature communications.