Nothing like a stuffy nose to ruin your day. You sound like a ponce, food tastes like cardboard and you have to sleep with your mouth open for spiders to crawl in. No joke. It happened to a friend of a friend of mine.
But have you ever noticed how quickly your sense of smell returns? Almost as soon as the sniffles are gone, you’re back to sniffing roses, and new research is finding out how our brain can adjust so fast to changes in sensory input.
What I love about this study is how they did it.
For a whole week, 14 people had their noses completely blocked during the day. At night, they slept sans-nose-blockers in a special low-odour hospital room.
A low odour hospital room? All the ones I’ve been to smell weirdly like custard. I wonder if all 14 shared the same room, or if they were spread out… I mean, even if you do have a spesh no-custard hospital dorm, if 14 people spending the night there it won’t be low odour for long.
Brain activity in response to odours changed after a week of smell deprivation in two regions. Activity increased in the orbital frontal cortex, but decreased in the piriform cortex, both are related to our sense of smell.
“These changes in the brain are instrumental in maintaining the way we smell things even after seven days of no smell,” said lead author Keng Nei Wu, Northwestern University Feinburg School of Medicine, in the press release.
“When your nostrils are blocked up, your brain tries to adjust to the lack of information so the system doesn’t break down. The brain compensates for the lack of information so when you get your sense of smell back, it will be in good working order.”
Once the 14 participants were released to sniff wildly, their brains soon returned to normal, showing pre-experimental levels of excitement when offered something smelly.
This rapid reversal in the realm of smell is quite different to sight, where deprivation usually has longer-lasting effects. Wu suggests this could be because smell deprivation is pretty common, given our penchant for catching colds and having allergies. Perhaps it has evolved to be more agile, or perhaps the endless sniffles we get in primary school gave our brains ample chance to practice.
Either way, it seems the quick adjustments by our brains protect our sense of smell, so it can rebound quicker than you can say “the one who smelt it dealt it.”
Wu ends by saying “more knowledge about how the system reacts to short-term deprivation may provide new insights into how to deal with this problem in a chronic context.”
Chronic loss of smell is nothing to be sniffed at (lol.) It really takes the fun out of life. This column, 20 years of living without a sense of smell, was clearly written from the pits of despair for want of a whiff of fabric softener.
Keng Nei Wu, Bruce K Tan, James D Howard, David B Conley & Jay A Gottfried (2012). Olfactory input is critical for sustaining odor quality codes in human orbitofrontal cortex
Nature Neuroscience : 10.1038/nn.3186