Thursday, February 17, 2011


This is your brain:

That's what I'll be learning about for the next couple of months.  For about 4 weeks, we'll be doing the anatomy of the brain, brain stem and spinal cord.  After that is spring break (whoo) and then we'll come back to do the "touchy feely" stuff - which is the behaviour / psychology part of the Brain & Behaviour course.

B&B is apparently the hardest course at Penn Med.  Period.  And I thought my last class (MDTI - mechanisms of disease and therapeutic interventions) was bad.  The only redeeming quality is that the material is totally super awesome

Unfortunately, it's only been a week and a half and I'm already a few days behind in class.  This is after putting in 5+ hours every day trying to keep up (ok, I completely goofed around the last weekend and did no studying - so maybe that's why, but it was totally worth it!).

Getting slammed by this much information makes me feel kinda small and stupid.  I mean, yes I understand this is really complicated stuff, but my mind doesn't seem to care.  As of now, this is how my brain feels:

Here's something interesting I've gotten out of the last week and a half.  There is a sensory homunculus in the somato-sensory cortex of the brain.  When all of your senses come back into your brain, they are brought back in a very careful way so a map is made of your body.  So if you stimulate your toe, one specific part of your brain lights up.  Stimulate your pinky, a different part lights up.  This map of your senses is called the homunculus:

The brain has a big fissure in the middle that goes from the front to the back of the brain.  The homunculus is approximately the same on the left and right side of the brain (representing the right and left side of the body). 

Speaking of your toe - ever wonder why foot fetishes are so common (actually, I think they are the most common "deviant" sexual practice)?  Take a close look at the medial part of the homunculus - professors joke that it's like your "feet are dangling over the edge into the deep parts of your brain".  Well - there's something else dangling down there too: sensation from your genitals.

Referred pain and crossed information pathways leading to "misplaced" information is not uncommon in the brain.  Sensation from the toes is very closely placed to sensation from the genitals.  So if you stimulate your toes... let's say "vigorously", I can see why some cross stimulation might happen in the genital part of the homunculus map.  It's also possible that some people have an unfortunate (or fortunate, depending on your perspective) cross in neuronal pathways leading to a large overlap in the toe/genitals map.

So there you have it, a possible biological reason why foot fetishes are so common. Am I backing this up with scientific studies?  No.  Conjecture is so much more fun for topics like this.

Learning about brains is so awesome.

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