Exposure to Certain Fragrances During Sleep Boosts Cognitive Function Mike McRae - Science Alert
go to original October 7, 2023

Aromatic oils could help work the brain by enriching the environment with smells. (Getty Images)

Of all the senses we love to indulge, scent is often neglected – but the right smells could be just what your brain needs to keep it whirring in old age.

Researchers at the University of California, Irvine recently uncovered strong evidence that enriching the air with fragrances improves cognitive performance by strengthening a critical connection between neurological areas involving memory and decision-making.

Their experiment, involving 43 men and women aged 60 to 85, suggests cognitive decline and conditions such as dementia might be slowed by simply diffusing a different choice of perfumes through the bedroom before bed each night.

Keeping the old gray matter stimulated as we age is vital to maintaining good cognitive health. That doesn't just mean keeping up with the daily crossword – it means peppering our environment with all kinds of sights and sounds for the brain to chew on.

For other animals, enriching the environment with odors has been shown to stimulate neuroplasticity, especially in tests involving animals with human-like symptoms to neurological disorders.

It's not exactly a stretch to believe humans could also benefit from experiencing a complex 'scent-scape'. Physiologically speaking, our ability to detect smells deteriorates before our cognitive ability begins to decline.

Losing this sense also correlates with a loss in brain cells, hinting at a strong connection between smell and neurological function.

"The olfactory sense has the special privilege of being directly connected to the brain's memory circuits," says neurobiologist Michael Yassa.

"All the other senses are routed first through the thalamus. Everyone has experienced how powerful aromas are in evoking recollections, even from very long ago. However, unlike with vision changes that we treat with glasses and hearing aids for hearing impairment, there has been no intervention for the loss of smell."

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