According to this article on NBCNews.com –
“After a smell enters the nose, it travels through the cranial nerve through the olfactory bulb, which helps the brain process smells. The olfactory bulb is part of the limbic system, the emotional center of the brain. As a member of the limbic system, the olfactory bulb can easily access the amygdala, which plays a role in emotional memories (it’s also where the ‘fight or flight’ reflex comes from).
‘Olfactory has a strong input into the amygdala, which process emotions. The kind of memories that it evokes are good and they are more powerful,’ explains Howard Eichenbaum [Howard Eichenbaum, director of the Laboratory of Cognitive Neurobiology at Boston University].
This close relationship between the olfactory and the amygdala is one of the reason odors cause a spark of nostalgia.
‘We don’t use emotional memory that much,’ says Dr. Ron DeVere, director of the Taste and Smell Disorders Clinic and the Alzheimer’s Disease and Memory Disorders Center, in Austin, Texas, and member of the American Academy of Neurology (AAN). He adds that when people consciously attempt to remember something they focus on the details, not feelings.
“You have an odor, you may not identify the odor, but you are associating that with some memories. The first time you smelled apple pie you may have been at your grandmother’s house,’ DeVere says.
Also at play is a relationship between the olfactory system and the hippocampus, which is critical to developing memories. Even though the olfactory system interacts with the emotion and memory centers in the brain, it does not connect with more developed regions.
‘Smells do bring back memories,” says Dr. Ken Heilman, James E. Rooks Jr. Distinguished Professor Neurology and Health Psychology at the University of Florida and a member of AAN. “Smell goes into the emotional parts of the brain and the memory parts, whereas words go into thinking parts of the brain.’
This could explain why memories sparked by smell feel nostalgic and emotional, rather than concrete and detailed. Also, Eichenbaum notes that primates evolved to rely mostly on vision, not smell, so these memories are less reliable.
‘When you smell things you remember your emotions … it’s very, very true,’ says Heilman.”
We hope you’ve enjoyed a little smell for thought. And, the next time a smell transports you back to a specific time or place, you’ll know the reason why.
THE PROUST EFFECT
“Soon, mechanically, weary after a dull day with the prospect of a depressing morrow, I raised to my lips a spoonful of the tea in which I had soaked a morsel of the cake. No sooner had the warm liquid, and the crumbs with it, touched my palate than a shudder ran through my whole body, and I stopped, intent upon the extraordinary changes that were taking place. An exquisite pleasure had invaded my senses, but individual, detached, with no suggestion of its origin…
…And suddenly the memory returns. The taste was that of the little crumb of madeleine which on Sunday mornings at Combray, when I went to say good day to her in her bedroom, my aunt Léonie used to give me, dipping it first in her own cup of real or of lime-flower tea. The sight of the little madeleine had recalled nothing to my mind before I tasted it; perhaps because I had so often seen such things in the interval, without tasting them, on the trays in pastry-cooks’ windows, that their image had dissociated itself from those Combray days to take its place among others more recent; perhaps because of those memories, so long abandoned and put out of mind, nothing now survived, everything was scattered; the forms of things, including that of the little scallop-shell of pastry, so richly sensual under its severe, religious folds, were either obliterated or had been so long dormant as to have lost the power of expansion which would have allowed them to resume their place in my consciousness. But when from a long-distant past nothing subsists, after the people are dead, after the things are broken and scattered, still, alone, more fragile, but with more vitality, more unsubstantial, more persistent, more faithful, the smell and taste of things remain poised a long time, like souls, ready to remind us, waiting and hoping for their moment, amid the ruins of all the rest; and bear unfaltering, in the tiny and almost impalpable drop of their essence, the vast structure of recollection.
And once I had recognized the taste of the crumb of madeleine soaked in her decoction of lime-flowers which my aunt used to give me (although I did not yet know and must long postpone the discovery of why this memory made me so happy) immediately the old grey house upon the street, where her room was, rose up like the scenery of a theatre to attach itself to the little pavilion, opening on to the garden, which had been built out behind it for my parents (the isolated panel which until that moment had been all that I could see); and with the house the town, from morning to night and in all weathers, the Square where I was sent before luncheon, the streets along which I used to run errands, the country roads we took when it was fine. And just as the Japanese amuse themselves by filling a porcelain bowl with water and steeping in it little crumbs of paper which until then are without character or form, but, the moment they become wet, stretch themselves and bend, take on color and distinctive shape, become flowers or houses or people, permanent and recognizable, so in that moment all the flowers in our garden and in M. Swann’s park, and the water-lilies on the Vivonne and the good folk of the village and their little dwellings and the parish church and the whole of Combray and of its surroundings, taking their proper shapes and growing solid, sprang into being, town and gardens alike, from my cup of tea.” – Marcel Proust, Swann’s Way