11 May 2023

We’ve all experienced a moment when a smell suddenly brings back memories. A whiff of perfume, a hint of cinnamon and clove, even the smell of furniture polish can send us back in time with vivid detail.

The reason is that our olfactory bulb which processes smells is physically connected to the two places in our brain that process emotion and memory, the amygdala and hippocampus. The link makes a lot of sense in animals that use pheromones for sexual attraction.

This strange entanglement of emotions and scents may actually have a simple evolutionary explanation. The amygdala evolved from an area of the brain that was originally dedicated to detecting chemicals, Herz said. “Emotions tell us about approaching things and avoiding things, and that’s exactly what the sense of smell does too,” she said. “So, they’re both very intimately connected to our survival.”  In fact, the way we use emotions to understand and respond to the world resembles how animals use their sense of smell.

— Live Science: Why smells trigger memories

Which brings me to this plant I found blooming at Hays Woods in late April. The scent of cypress spurge (Euphorbia cyparissias) is so unique that it takes me back to a particular place and time and the happiness of seeing beautiful birds at Presque Isle State Park in early May.

On Throw Back Thursday here’s why cypress spurge reminds me of migrating warblers:

A Smell That Reminds Me of Warblers

p.s. Smells aren’t always happy. Unfortunately our brains can associate a smell with a traumatic experience so that the scent causes PTSD flashbacks.

(photos from Wikimedia Commons and Kate St. John)