My Brain!

Yes, that's me. This is one view of a structural image of my brain. I got scanned for about an hour (in terms of MRI studies, that's pretty long!) at work in order to test out our protocol before we tried it on stroke patients. I think being scanned provided me with a very good understanding of what we ask participants to do in a study. Scanning is certainly not terrible for me (at some points, the table vibrates, so it's kind of like a back massage), but for anyone who doesn't like loud noises or earplugs or enclosed spaces, I can image that it's not very pleasant.



For the past two weeks, I've been helping Arnaud to run a study of patients who have either had a stroke or shown signs of hemispatial neglect (or both). In this study, Arnaud runs a series of neuropsychological tests to determine each patient's cognitive level and the severity of neglect. Some of the tests include the Mini Mental State Examination (which I described earlier, and you can see a pretty accurate copy of here: http://www.bami.us/MiniMental.htm), visual search tasks, reading tasks, drawing tasks, and bisection tasks. In the case of a patient suffering from severe neglect, he or she might only read the words on one side of a paper, copy one half of a drawing (or one half of each element in a drawing), or only be able to find elements on one side of a visual search. After the tests, we've been scanning patients to obtain structural images (like mine, above), functional images of patients' brains while they complete a task involving memory, bisection, and search, and also diffusion tensor images (DTI). DTI are those that I'm least familiar with, but I find them really fascinating! Basically, they're used to find white matter connections within the brain by tracking the diffusion of water. The physics behind this type of scan is really cool! It involves rotating the magnetic field in many different directions in order to determine which protons (in this case, they're hydrogen atoms in the form of water molecules) have been displaced during the scan. DTI can be used to find the white matter connections and also to determine what direction water travels within the brain. You can check out a bit of background on DTI and white matter here: http://www.scientificamerican.com/article.cfm?id=white-matter-matters



The scanning has been interesting because the structural images come up on the computer screen while we're completing the 40 minute scan. None of the individuals doing the scanning have been trained to read structural scans like a radiologist, so none of us know exactly what we're looking for in terms of brain lesions, but in some patients, the lesions are incredibly obvious. There was a woman on Friday with a very large portion of her brain missing in the structural scan, and by meeting her, I would have never known it. She drove herself to the lab, walked fine, talked fine, showed no cognitive problems in the tests, and seemed to be just like everyone else with a fully intact brain. It's terrible to think of anyone suffering such a large brain injury, but at the same time, the brain's ability to recover amazes me.



One of the coolest aspects about work so far has been everyone's willingness to teach me something. I've been learning about the MRI technology itself whenever we're scanning and some of the operators have helped to explain some of the physics involved with the magnetic field, etc. I've been working on learning how to use MATLAB (apparently, the computer program for nearly every type of science) and a Statistical Mapping toolbox that's used to pre-process the "raw" fMRI images. This is really interesting for me because I'm pretty inexperienced with computers, but it's really been helping me to understand more about brain imaging technology. In one of the offices I work in, I've been talking with a postdoc about her work on imaging the brains of patients with Mild Cognitive Impairment (MCI) in order to try to determine structural differences between MCI patients who develop Alzheimer's Disease and MCI patients who don't develop it. This is done in an attempt to catch Alzheimer's Disease before it's too late. Another researcher was explained her work on sleep the other day and taught me how to recognize the different stages in the context of an EEG (or electroencephalogram). She finished a study recently in which participants were conditioned to associate a specific tone with specific information, went to sleep in an EEG lab, and then the tone was played when the participants entered REM sleep. The EEG showed that the brain did respond to the tone, even though the participants didn't necessarily wake up. This has some interesting implications about memory enhancement that could be done subconsciously during sleep.



So far, I have attended at least two seminars a week, and so I've heard lectures (in English and French) on a ton of different topics! Some of the more interesting studies have included imaging the brains of mothers with Post Traumatic Stress Disorder while they watch videos of themselves interacting with their children (as compared to mentally healthy mothers), using stem cells to treat Multiple Sclerosis, and comparing brain images of professional musicians to those of nonmusicians when listening to classical pieces ending in disharmonious chords. These talks have been great as well because I've been able to hear from researchers from all over on studies that haven't even been published yet.

That's all for now, but please post questions and comments if you like! I realize that this post might be more technical than the others, so if you want to know more about anything that I mentioned - let me know!