Science Fail Monday: How a dead salmon taught us about statistics

Any scientist knows the importance of a good negative control. A negative control in an experiment is a group of samples or subjects in which no response is expected to an experimental treatment. The experimental group can then be compared to the control group. Such negative controls are gold standards in science and are supposed to provide confidence in experimental results. However, occasionally, a negative control gives unexpected and hilarious results worth of an Ig-Nobel Prize, the highest honor for scientists who publish the silliest research. Such was the case in an experiment involving fMRI, human emotions, and an Atlantic salmon.

https://commons.wikimedia.org/wiki/File:FMRI_scan_during_working_memory_tasks.jpg

An example of an fMRI scan in a human. The red spots have higher brain activity when subjects are performing a memory task.

fMRI stands for functional magnetic resonance imaging. If you’ve ever had a knee injury or a concussion, you have likely experienced a normal MRI scan, which uses radio waves and a magnet to take a structural picture of the organ of interest. The “functional” in fMRI means that researchers can use MRI images to measure brain activity and take a snapshot of changes over time. When a strong magnet is turned on over the brain, the hydrogen atoms in all of the water molecules in the blood point in the same direction, like a compass needle next to a refrigerator magnet. When the magnet is turned off, the hydrogen atoms relax back to their original positions, which releases a signal. This signal changes based on how much oxygen is in the blood, so the end result is a picture of the brain with information about which regions have more oxygenated blood. Regions needing more oxygen are generally assumed to be more active. Researchers can even have study participants perform a task during an fMRI scan, such as viewing particular images or listening to music, and use the fMRI data to determine which areas of the brain are active during the task. These types of studies can tell us a lot about which brain regions are involved in everything from social situations to processing fear.

In the Ig-Nobel Prize-worthy experiment, researchers wanted to use fMRI to determine which parts of the brain were active in response to seeing human faces displaying different emotions. However, they needed a negative control for their human subjects just to make sure that any brain activity they saw in response to the faces wasn’t just due to chance. The ideal candidate for such a negative control? A four-pound Atlantic salmon, purchased by one of the researchers at the local fish market.

https://commons.wikimedia.org/wiki/File:Salmo_salar-Atlantic_Salmon-Atlanterhavsparken_Norway_(cropped).JPG

The authors of the IgNobel prize study used an Atlantic salmon like this one as their negative control.

The researchers put the dead salmon in their fMRI scanner and, for the sake of science, asked it what emotions it thought the humans were displaying in pictures flashed up on the screen in the scanner. The authors do not comment on the salmon’s responses, but it can be assumed that the salmon was not a model experimental participant and did not comply with the study directions. Expecting to see nothing, the authors analyzed the fMRI signal in the salmon’s brain before and after the salmon “saw” the photos of the faces. Imagine the shock in the room when a few spots in the salmon’s itty-bitty brain lit up like a Christmas tree, suggesting that it was thinking about the faces it saw. Duh duh duuuuuhh….zombie salmon?

Obviously, the salmon was not alive, nor was it thinking about the emotional state of humans. Luckily for the field of fMRI, instead of publishing a paper telling everyone they should use dead salmon to study human response to the emotions of others, the authors of this study delved deeper into why they were seeing “brain activity” in this very dead fish. In their original data, the researchers failed to correct for multiple comparisons: basically, because you are comparing so many brain regions to so many other brain regions, you’re much more likely to find a spot with significant activity in fMRI purely by chance (for more info on multiple comparisons, click here). The authors applied the appropriate statistical corrections to their data, and voila, no more zombie salmon. And then, because scientists have a funny sense of humor, they wrote up and published these results as a lesson to all on the importance of having a good statistician.

Peer edited by Claire Gyorke.

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Statistically significant insults for the soul: p < 0.05

Author’s forward

There are days in which a scientist finds herself needing to express her “mean genes.” When an experimental control fails, when Reviewer 3 sinks a paper, when someone drinks the last cup of communal coffee and fails to make more, the time has come to use a scientifically accurate and statistically significant insult. Simply insert your target’s name(s) and enjoy. Readers beware, what follows may cause Impostor’s Syndrome.

 Unvalidated research sponsored by the for profit Anti-Insult Foundation of America.


  1. You are a lissencephalic australopithecus.

     

    Illustration by Bailey Peck

  2. At the top of the bell curve, are you?

    Illustration by Bailey Peck


  3. You are a few edges short of a node.

     

    Illustration by Bailey Peck

  4. You spend a bit too much time in G0.

     

    Illustration by Bailey Peck

  5. You are the forgotten semicolon.

     

    Illustration by Bailey Peck


Peer edited by Marissa Cann
Many thanks to the Sethupathy Lab for the Insult Brainstorming Session!

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Science Fail Monday: Requiem for a Western Blot

Requiem for a Western Blot: A Haiku on Reversing the Positive and Negative Electrodes

Two weeks to prepare
It’s time to transfer this gel
Data finally?

Excitement building
Put the wires on backwards
Proteins all lost, $%!#

Western-blot-fail

 


PEER EDITED BY Bailey Peck AND chris givens

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This article was co-published on the TIBBS Bioscience Blog.

Inaugural Science Fail Monday: Filter Fail

filterfail-rage-face-300x300For weeks, I struggled to produce a successful harvest of lentivirus. I needed to transduce my pancreatic cancer cell lines with shRNA targeting my gene of interest. This is a common protocol in my lab, and I had never experienced difficulty accomplishing this task before. Now, I was unlucky beyond all reason. My plasmids were the correct sequence and intact. My transfection reagents were brand new. My packaging cells were boastfully glowing red with the mCherry from my cDNA transfection control. Yet, once harvested, no virus would infect my target cells, and my experiments were aggravatingly halted. With the despair only known to the senior graduate students living with that chasm of unfathomable emptiness in their innards, where that terrible voice whisper-shouting, “YOU’LL NEVER GRADUATE,” echoes brutally, I attempted my protocol once more. I stared hopelessly at the box of Whatman Puradisc PES 25mm, 0.20 micron syringe filters and… wait, what? 0.20 micron? These are supposed to be 0.45 micron. Are you kidding me?! For weeks I had harvested viral supernatant with a filter that had pores too small. I was extracting the virus right out of my supernatant, never to reach my target cells. Curse you, Whatman Puradisc PES 25mm, 0.20 micron syringe filters. Curse you.


PEER EDITED BY Chris Givens AND Erinn brigham

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This article was co-published on the TIBBS Bioscience Blog.