The Brain is Beautiful

Yup, that's a picture of a brain.  Who knew it could be so psychedelic?  My friend Laurie Pycroft found an amazing gallery of pictures of brains and neurons. 


The above is a cross section of H.M.'s brain (artificially colored, of course).  

H.M. was "an epileptic who went under the surgeon's knife at the age of 27--the doctors stopped his seizures, but they also cut into a brain region called the hippocampus and inadvertently destroyed his ability to form new memories. For the rest of his life, until he died in 2008 at the age of 82, he could only hold a thought for about 20 seconds. Yet H.M. could clearly remember things from before his surgery, and could also form new "motor memories"--for example, after many repetitions he performed a difficult drawing task with ease, but had no memory of doing it before. Such results helped researchers understand the role of the hippocampus, which is shown in cross-section at the bottom half of this 2005 image. "

Psych students are beaten to death with facts about H.M.'s bilateral lesions to the medial temporal lobes and the resulting deficits in his memory.  Still, I think it's worth mentioning that while H.M. could not consciously learn anything after his surgery, he could unconsciously learn how to complete new puzzles and learn the layout of buildings by experiencing things physically over and over again.  What's important here is that we seem to have different types of memory, conscious, "declarative" memories (e.g. remembering what you did yesterday), and unconscious, "non-declarative" memories (e.g. learning how to ride a bike, you can't explain it, your muscles just learn how to balance).

Here's another picture I love:

New neuroimaging techniques have allowed us to see some pretty awesome things.

"One new method called diffusion MRI reveals major axon pathways by tracking the flow of water molecules through the brain. While the technique is still under development, researchers think it may have many useful clinical applications. This diffusion MRI image, from 2008, shows the brain of a patient who suffered a stroke in the thalamus and midbrain, resulting in broken and disrupted axon tracts (visible at bottom). Each line represents thousands of axons."

Check out the rest of the pictures at: http://discovermagazine.com/photos/17-the-brain-is-ready-for-its-close-up