Sep. 20th, 2009

xiphias: (Default)
http://prefrontal.org/files/posters/Bennett-Salmon-2009.jpg

That's a jpg, which, obviously, those of you who are blind won't be able to see. So let me extract a couple of the important quotes:

METHODS
Subject. One mature Atlantic Salmon (Salmo salar) participated in the fMRI study.
The salmon was approximately 18 inches long, weighed 3.8 lbs, and was not alive at
the time of scanning.
Task. The task administered to the salmon involved completing an open-ended
mentalizing task. The salmon was shown a series of photographs depicting human
individuals in social situations with a specified emotional valence. The salmon was
asked to determine what emotion the individual in the photo must have been
experiencing.
Design. Stimuli were presented in a block design with each photo presented for 10
seconds followed by 12 seconds of rest. A total of 15 photos were displayed. Total
scan time was 5.5 minutes.


Okay? Putting a dead salmon into a MRI and asking it about the emotional contexts of various photographs ought to put one into consideration for an Ig.

However, in order to actually get an Ig, the research has to actually demonstrate something useful, not just be weird. Why were they doing this and publishing the results?

Because they found data that made it look like the dead salmon WAS doing things.
With the extreme dimensionality of functional neuroimaging data comes
extreme risk for false positives. Across the 130,000 voxels in a typical fMRI
volume the probability of a false positive is almost certain. Correction for
multiple comparisons should be completed with these datasets, but is often
ignored by investigators. To illustrate the magnitude of the problem we
carried out a real experiment that demonstrates the danger of not correcting
for chance properly.


So. THAT'S what makes it Ig-worthy. They MRI-scanned a dead salmon, on purpose, to demonstrate the baseline random-chance error, and show how it can make things LOOK like statistically-significant things are happening, even when you're, y'know, scanning a dead salmon. That's useful.

In other words, I think this is a shoo-in. First, it makes you laugh -- but then, it makes you think.

November 2018

S M T W T F S
     123
45678910
11121314151617
18192021222324
252627282930 

Most Popular Tags

Style Credit

Expand Cut Tags

No cut tags