Smelly ode to HM

Hey, it's Saturday! Saturday has officially become the farmer's market trip day, bake kale chips, eat all said kale chips, and then eat what my other half (MOH) decides to bake. MOH's been really into baking lately.

My my, what beautiful feet you have my lovelies!

It started off real innocent with trying to master macarons, which after several batches, not wearing a belt anymore, and now sporting a maca-belly, the final product was ah-mazing. I figured after getting macarons down, MOH was going to hang up his apron, but the cookies, brownies, custards, and cupcakes keep coming.

This weekend MOH's decided to make the best of our last quinoa batch (I made the stupid mistake of buying quinoa in bulk), and he decided to make almond cranberry quinoa cookies (bon apetit inspired recipe). Absolutely delicious - the cookies taste like scones with a great bite from the crunchy quinoa. Seriously, if you like quinoa, or have lots of it to use, I'd strongly suggest trying to use your leftover quinoa for making a savory dessert. And this cookie tastes great with tea! These cookies smell good, too. Really good. There's that great lingering aroma of baked goodness and the cranberry/almond mixture is so tantalizing.

It's funny how much better things taste when they smell good. It sounds so DUH, but it's really amazing how much smell contributes to our perception of good food. For me, nothing beats scarfing down a cookie hot out of the oven (burns my fingers, but so good going down). That smell of molten chocolate chips can brighten up any day for me. Then there's the opposite, when food smells too alien that any interest in trying it is lost. Case in point: durian. The foot-like smell of durian is too much for some people to enjoy this exotic fruit - if you're really daring, I'd strongly suggest durian ice cream!

Thinking about how much smell affects our ability to appreciate food, I thought about if there were any documented cases of individuals with brain deficits that also had any problems with discriminating smell. Doing a quick search, I came across a really famous patient named HM who was well known for having an inability to create new memories. If you've taken any neurobiology or learning/memory classes, you're probably familiar with the famous HM. HM was a male who suffered with cerebral seizures for many years before finally getting a surgery at age 25 to treat his epilepsy.

The surgery removed HM's medial temporal lobe, including the brain regions called the amygdala, parahippocampal gyrus, and hippocampus (Scoville et al., 1953). While the amygdala was already documented as being important for emotion, the parahippocampal gyrus and hippocampus were relatively unexplored in terms of memory.

While the seizures were gone, HM's ability to form new, declarative memories was affected. Declarative memory is the ability to remember facts or knowledge. Non-declarative memory refers to unconscious memories and skills (like riding a bike). His working, non-declarative memory was intact, as he could do several motor tasks just as good as any normal subject. While he faced severe anterograde amnesia, or the ability to form new memories, his childhood memories as well as most past memories (retrograde amnesia) were relatively intact (Scoville et al., 1957). HM's unique case really opened the field of neuroscience in providing insight into different memory types as well as demonstrated how different brain functions are localized within the brain. What I didn't find out until recently though was his memory deficits also included olfactory deficits, or the ability to identify aromas  (Eichenbaum et al., 1983). 

In HM's case, HM was able to tell different concentrations of food, but couldn't tell the difference between different odors. He described several common odors incorrectly, oftentimes giving descriptions of the odors that had no relation to the odor itself. Some examples included describing raspberries as smelling like "carrion, like a squirrel," or vanilla like "freshly made paper." He could still smell, and was able to identify the odors when given a visual cue, but his ability to discriminate odors was severely impaired (Eichenbaum et al, 1983). 

Beautiful photo of canh chua, courtesy of Jason Hutchens

Imagine if you had to go about your everyday life with the inability to smell. It's something that we take for granted, and sometimes we even wish we didn't have (you know those times). But without the ability to smell, the enjoyment of food drastically changes. Probably half the enjoyment behind having great food is taking in the variety of different aromas that culminate together to create this cohesive dish. Think about how much food sucks when you're sick - I personally feel that everything I eat tastes like salted water when I'm not feeling great. I think the best part of eating things like a really good pasta dish is the fragrant basil, or pesto topping, or the deep aromatic tomato sauce. 

So the next time you're out and about town, maybe hanging at your favorite food truck, or dining at that cute hole-in-the-wall lunch joint, take a moment to smell all the different food aromas that are surrounding you. We don't even consider how much smell can affect our interest and desire to take in that additional cake slice, or that additional helping of sour tamarind soup (canh chua) on a cool day. 

Happy dining all! 

PS. If you were interested in learning more about how sensory information like smell and taste is processed in the brain, tune in for next week's posting! 

References:

Scoville et al., 1953. Observations on medial temporal lobotomy and uncotomy in the treatment of psychotic states. Research publications - Association for Research in Nervous and Mental Disease. 31: 347-73.

Scoville et al., 1957. Loss of recent memory after bilateral hippocampal lesions. Journal of Neurology, Neurosurgery and Neuropsychiatry. Feb; 20(1):11-21.  

Eichenbaum et al., 1983. Selective olfactory deficits in H.M. Brain. 106: 459-72.