Monday, March 5, 2012

The 21st Century Brain | Special Series | Big Think

Smell: A powerful example of contextual memory – and contextual decisions
Let me take a concrete example: one of the most powerful contextual cues that exists, smell. Just like posture, the actual, physical position of our bodies, can affect how we feel and the subsequent decisions we make (as I describer earlier in the week), so too can other bodily cues affect the memories we retrieve. When we smell, we remember—in fact, research has shown that the memories associated with smell are the most powerful of all—and what we smell affects what we remember, how we subsequently feel, and what we might be inclined to decide as a result.
This causal chain is explored in beautiful detail in the memoir Season to TasteMolly Birnbaum’sexploration of her loss of smell. She describes the impact of anosmia (the inability to smell) on her psychological state and her life more broadly, and just as she wonders how important a role smell plays in things as deceptively simple as eating and as unmistakably complex as choosing a significant other, we wonder how many of her choices are impacted by the inability to smell – and how many were once affected by the previously unquestioned presence of smell.
Smells in the environment trigger associated memories, that may or may not be relevant to a decision we’re making. And if we’re lucky enough to never have experienced the loss of smell, we, unlike Birnbaum, will likely pay no attention to either the smell or the associated thoughts and emotions.
So let’s go back to our car purchase. Imagine that at the moment you’re in the lot, someone walks by with a mug of steaming hot chocolate. You might not even remember that he passed, but the smell triggers memories of your grandfather: he used to make you hot chocolate when you spent time together. It was your little ritual. And before you know it, you’re buying the wrong car, without even realizing why.
Now, imagine a different scenario. This time, there’s a pervasive smell of gasoline: the lot is across the street from a gas station. And you remember your mother warning you to be careful around gas, that it could catch fire, that you could get hurt.  Now, you’re focused on safety. You’ll likely be leaving the lot with a car that is quite different from your grandfather’s. And again, you probably won’t know why.