Repost: Life as a Guinea Pig: The Pain Study

Apr 26 2010 Published by under Academia

Sci would like to note that she is without internet for the next few days for various reasons. Thus, there is a repost. Play nice on the internet everyone, or I'll send the Evil Monkey after you. He bites. :)
Over my years as a grad student, I've been a guinea pig for more than a few research studies. Most of the people leading the studies are fellow grad students (I'm never involved with the work at all), and it's good to help them out. A lot of times the studies are kind of cool (like that one with caffeine and the brain). And Sci has a dream. One day, I really want to see a picture of MY BRAIN in an fMRI scan on the cover of Science. Ok, I won't be too picky. I'll take J. Neuroscience. Honestly, I'd probably take Brain Research. Seriously, that would make me so geekily proud. I would ask for a copy, and get it printed out big, and frame it on my wall. "THIS is your brain on SCIENCE!"
But I'll admit, I'd probably participate a lot less if I didn't get paid. I know, I know, I'm bad. I shouldn't sell myself to science for money. But we grad students are poor. My cat needs food, and I really prefer to feed my little carnivore food that doesn't contain corn as the first ingredient. I also like eating healthy food once in a while. So I volunteer. These are not clinical trials for drugs or anything. Instead, these are basic research studies where they need human volunteers to see how the brain and body works.
And then of course, there's the certain amount of machismo. And that's where the get to my current study, which my fellow grad student has graciously given me permission to blog. The pain study.
The pain study has been going on at my MRU for a while, and has...a certain reputation. Many of my fellow grad students are guinea pigs in the service of science, and we have fun telling our war stories. There's the friend of mine who ate a diet (don't worry, it was a full 2,000 calories, and adjusted so that she neither gained nor lost weight, and completely nutritious) composed of ONLY what the researchers gave her, and had to collect every bit of...anything that came out...for two months. There was the caffeine study where I drank 12 cups (cups as in the unit of measure, it was a whole pot) of coffee a day for three weeks, and then went through 48 hours of withdrawal (the original high levels of coffee drinking were self-imposed prior to the study, don't worry, and I've since cut back to one caffeinated drink per day, and only when I really need it). There's the study where they give you a cold, and you're not allowed to treat the symptoms at ALL.
But to all of these, the real veterans give you a raised eyebrow and say "yeah, but have you done the pain study?"


The pain study is a rite of passage. From what I'd been told, it was akin to getting paid for torture. So when my friend asked for more research volunteers, I wasn't exactly standing in line. But times are hard, and it's $130. And only one scanning session. And I've always been curious. I've always thought that I was a total wuss for pain, but what if it turned out I was a super(wo)man or something? I wanted to know. And how bad could it be? I signed up.
First, I went in for training. The first half of the training is paperwork. You read and sign forms, wherein you are explained the exact nature of the study, what exactly will occur, and any possible side effects (the only possible side effect from this one is the possibility of a mild burn, and then it's only if the equipment malfunctions. In the event of you getting injured, they will pay for EVERYTHING). And of course, you can back out at ANY time. This should be taken very seriously. NEVER keep participating in a study if you feel uncomfortable with what is taking place. I have actually backed out of a study (I wasn't feeling well), and everyone is always very understanding.
In this case, because it's an MRI study, they also did a bit of a health history, to determine if anything could affect my ability to have an MRI. I've been cleared for these things before, so all was fine. And finally, they had me fill out a questionnaire on my handedness. Believe it or not, handedness can have a big effect on brain scans. I'm sure you've heard "only left handed people are in their right minds", but the reality is, they ARE. For certain tasks, left handed and right handed people actually have brain activation that is different. So for some studies, they will only recruit right handed people. Luckily, for this study, it didn't matter (Sci is very left handed).
Then came the actual training part of the study. First, I sat in a chair, while a little square electrode (about 1 inch square) was placed on my leg. This study works with heat pain (doesn't draw blood, doesn't do damage at the temperatures they were using, and doesn't leave a mark), so the electrode was heated up to various degrees, and I was supposed to rate (1) how much it hurt, and (2) how much the pain got to me. The pain was never supposed to be unbearable, and they had carefully chosen degrees of pain that were about at the limit of what you could tolerate (49 degrees Celsius, warm temperature is 35 degrees Celsius). Testing the pain range is an important step, you need to determine whether a given subject tends to rate their pain low (either out of machismo or just being insensitive to pain) or high (a diva, or just someone very sensitive to pain). You can then use the values during training as a baseline when you're looking at the values they give you in the actual study. So sometimes the electrode was just slightly warm, and sometimes it was..owie.
Then they ran me through the protocol I was going to experience in the MRI scanner. This particular study was done with arterial spin labeling MRI. This kind of MRI doesn't involve radioactive tracers (like PET imaging would), and is mostly designed to look at changes in cerebral blood flow. Cerebral blood flow is considered to be a decent indicator of brain activity, as the cells that are firing most need the most oxygen and food, and so blood will go to that area. In this case, the idea was to put me in pain, and look at where exactly the blood flow went in my brain, and how much blood flow there was relative to the amount of pain that I said I was in. But they don't want to put me in almost-unbearable pain for the ten minutes at a time required to get a good picture. So in this case, the electrode came on and went off for 30 seconds each time, and oscillated for 8.5 minutes. Then I would be recorded for 8.5 minutes with no heat on at all. So in the training, I underwent a test where they did the 8.5 minute section of pain. It wasn't so bad, I was chatting with the grad student and all was well. The grad student ran the study, and even served as her own guinea pig for the initial runs (not included in the data, obviously, that's conflict of interest), so she could tell me what to expect.
A few days later I came in for the real MRI. The MRU I'm at actually has an MRI center, with a special MRI dedicated to research use. You don't want to be horning in on the clinical MRIs when patients may need them. I'd seen this MRI before, the tech and I had even previously traded aloe cuttings. After removing all things that could possibly be metal from my body (taking out my piercings takes some time, there are a lot), I lay down on the bed for the scanner. I got some nice warmed blankets to keep me comfy during the study, since lying still will get you very cold after a while. I LOVED those warm blankets. Best part of the study, no question. Everyone should have a blanket warmer in their house. The electrode was placed under my leg (a different position each time), and a bulb was placed in my hand, which I could squeeze to alert people that I wanted to stop.
Then they fixed my head so I couldn't possibly move it. MRI photos take a long time (8.5 minutes, in fact), and you need to hold very still. Luckily, unlike those old-timey photos where you had to hold very still and no one is ever smiling, no one now just expects you not to move. Instead, your head is placed in a little cradle, and pads are placed around your head to keep it from moving. I also got some earplugs for the noise (MRI scanners are LOUD). Then they slid me in.
MRIs are not for those with claustrophobia. The tube is only about 20 inches high, and there's not a lot to see while you're in there except the little tunnel you're in. Luckily, I was told to lie with my eyes closed. And not to fall asleep. For the first few minutes this was tough, while they took baseline scans, with no pain, just lying there in a little tube with warm blankets on me, with my eyes closed. For a sleep deprived grad student such as Sci, that's almost too much of an invitation. But I managed.
After the baseline, the pain sessions started. There were four of them, each one followed by an equal period of rest. So the electrode came on and oscillated for 8.5 minutes, then went off for 8.5 minutes, then on, etc. And I have to say it wasn't that bad. The pain wasn't unbearable, though it was annoying. The hardest part was not moving my leg. You have pain circuits in your extremities (in your feet and hands especially) that go directly to your spinal cord. So when you touch a painful stimulus, impulses go directly to the spinal cord, the spinal cord activates muscle, and your body pulls itself away, often before you've even consciously realized you're in pain. And my leg was on a stimulus that was just enough to excite that circuit. Overriding that reflex takes WORK. And even so, my leg twitched like anything. I had to repeat in my head "do NOT move", and even then I'm sure the blankets were wiggling. So I wouldn't call the study torture, I would call it annoying. But I did my best. (Edit: Having now received a tattoo, Sci can say that the experience is roughly equal, except for the tattoo the consequences are even WORSE if you move.)
pain reflex.jpg
Your pain reflex circuit. This is what Sci was fighting the whole time.
The pain sessions came and went, and in between I tried not to fall asleep. After every session of pain and every session of rest, I had to rate the level of pain I was in on both scales. But even so, it didn't seem to take the full two hours it really did. Four sessions later I was slid out of the scanner and got on my way. But not without asking what my pain scores were like first. I always thought I would be a wuss for pain, but it turns out that I'm about average. I often wonder how many people think they are wusses or are inhumanly tolerant of pain, only to be proved wrong when the numbers get crunched. While I could wish that I was all tolerant of pain, I'm satisfied with average.
And the best part, Sci got a picture of her brain!!! Even if it never gets on the cover of a journal, it's right here, on the site. You can see it in the upper left. Isn't Sci's brain pretty on pain?

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3 responses so far

  • Anni says:

    Hold on, I'm not the only one that staunchly fed my two cats snooty food while I was getting by on rice and beans many nights? (And will for many more... still a lowly undergrad BS.) It's good to hear I'm not alone... and I have to admit "this is your brain on SCIENCE" would be freaking amazing.

  • canuck_grad says:

    "The pain sessions came and went, and in between I tried not to fall asleep."
    .... sounds like labour lol

  • [...] they tested their pain threshold compared to people who were just sitting around. I've been in a pain study before. This one appears to be a bit milder than the one I was in, the pain episodes look a lot shorter. [...]