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I'm in a psychology lab and we're having trouble getting participants for an fMRI study. We pay $150 per subject and we need to have several hundred healthy controls for one study. For the 20-minute study, the participant has to look at certain words and think about them, like imagining a scenario where "family" or "pride" was important.

We keep finding participants from recruiting around campus who will seem enthusiastic, then fall asleep immediately in the scanner. Our IRB states that we have to let them sleep for the full scan and pay them the full amount. I don't know how to prevent this. We've wasted thousands of dollars and weeks to months of time running studies with garbage data. Has anyone figured out how to recruit better participants?

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    Change the contract based on paid for viable results. One pays for "work" completed... Otherwise I am worth a fortune.... –  Jul 02 '19 at 20:21
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    @SolarMike, for that you need to go back to the IRB, I think. –  Jul 02 '19 at 20:23
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    @Buffy probably, but it was badly written to leave a loophole like that... To make it the equivalent of "sleep in our MRI scanner for an hour and get $150 for the privilege" and that does not even take into account the hourly cost of the scanner... –  Jul 02 '19 at 20:27
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    You could keep your study the same but instead frame it as a study of boredom-induced somnolence. It would be in keeping with a time-honored scientific tradition of trying to make the most of uncooperative subjects, errr, participants :) – BrianH Jul 02 '19 at 20:28
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    I think you need to redesign your task rather than your subject recruitment. It sounds really boring to me. People learning meditation fall asleep all the time, for example. Blaming the participants is probably not the right approach. – Bryan Krause Jul 02 '19 at 22:31
  • I agree with the above comments. Can you include two breaks where they must stand up and do jumping jacks or something? – Danielle Jul 03 '19 at 01:46
  • @SolarMike our IRB specifically forbids results-based compensation of any kind. –  Jul 03 '19 at 17:03
  • @Buffy any reasonable solution is going to require an amended ethics approval. –  Jul 04 '19 at 00:06
  • Is it possible that word has gotten around campus that people can take a nap in the scanner and still get the $150? –  Jul 04 '19 at 05:21
  • Do a test first. Unpaid. To weed out the non performers. Do some study with follow on testing. And tell them that falling asleep means losing out in the second gig. –  Jul 03 '19 at 14:38
  • Tell your participants to think about and memorize the words. Quiz them on the words after they come out of the scanner. – Angela Pretorius Jul 07 '19 at 14:24

2 Answers2

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Based on my own experience as a student, the problem is probably not that your participants are lazy... the problem is that, like many university students, they're severely sleep-deprived.

While a student, I once agreed to participate in a friend's (non-MRI) study, which involved listening to sounds and clicking buttons in response. To my embarrassment, despite being enthusiastic about participating, I kept drifting off briefly during the study. I managed to complete it, but I'm sure my results were affected. I'm pretty sure that if I had ever tried to participate in an MRI study, I would have fallen completely asleep.

I don't have experience running MRI studies so I'm not really sure what to suggest to solve this problem, other than to try recruiting from less sleep-deprived populations, or redesigning the study tasks to be more engaging.

  • @rooty play random audio, assuming audio is not part of the results required... –  Jul 02 '19 at 20:41
  • Or redesigning the study to account for the phenomenon. –  Jul 02 '19 at 20:27
  • Oh, it also occurs to me that time of day is important -- my guess is that participants are much more likely to fall asleep during an early morning session than a midmorning/afternoon one. –  Jul 02 '19 at 20:32
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    We've analyzed time-of-day results and found no correlation between morning and evening, though subjectively it "feels" like morning subjects have done much better. –  Jul 02 '19 at 20:33
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    Does your IRB approval allow you to require your subjects to drink coffee? Only half joking. –  Jul 02 '19 at 20:41
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    Maybe, but my naps come just after lunch. But then, I'm older than the rivers and mountains. –  Jul 02 '19 at 20:33
  • We also can speak over a microphone into the scanner room, and we say "Please keep your eyes open" when we see them start to drift off, but this also hasn't worked. –  Jul 02 '19 at 20:38
  • I should also add that we're allowed to offer the subjects coffee, and even pause the study,let them drink coffee, and restart, but no subject has accepted coffee yet in either case. I'm not sure why. –  Jul 02 '19 at 20:35
  • The notion that students are so sleep-deprived that they couldn't stay awake laying down during a 20 minute study seems insane to me. Even more so if it's true... –  Jul 04 '19 at 04:57
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The problem is not your participants. It is your stimuli. They are too boring. Change them, or add a task participants must perform. It could be as simple as "Press a button to continue."

You will need to go through the ethics board again.

Anonymous Physicist
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  • I thought the experiment was much more practical, such as comparing reactions to different sets of words. –  Jul 04 '19 at 03:53
  • @PatriciaShanahan, yes, and thus it is hard to design the experiment so that you get a valid base line. "Stimulating" the controls just voids the experiment. I don't know the expected MRI difference between sleep and lying down quietly. But it isn't my field. –  Jul 04 '19 at 00:29
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    @Buffy The only time I lie down flat with no entertainment, nothing to read, no TV is when I intend to go to sleep. I think even with the sleep opportunities of a retiree, not a student, that design would put me to sleep. –  Jul 04 '19 at 00:24
  • @PatriciaShanahan, If I read it correctly, the problem is with the control group who are not given the words so that the scans of the test group can be compared to a base. Making the control group active might invalidate their use as a control. I think the design issue is fairly deep. –  Jul 04 '19 at 00:20
  • I think the lack of any action the participant has to take other than thinking might be part of the problem. Could you add an action at the end of each word display, such as pick the picture that most closely relates to the scenario they imagined? (with IRB approval) –  Jul 04 '19 at 00:11