FMRI Shows Man Loves Wife More Than Angelina Jolie

An anonymous reader writes "We've discussed (at length) functional MRI technology as it pertains to marketing and virtual reality, but now Esquire writer A.J. Jacobs has become the first person to go inside the controversial machine to test the science behind his sex drive. As in, he has fMRI experts read his mind as to whether he's actually more turned on by his young wife or Angelina Jolie. The results, unsurprisingly, are both geeky and hilarious. Would you subject yourself to this kind of reality check?"

Comments

Brick Wall? Head. Head? Brick Wall.

[DynaSoar]

Myself and others wax scientific and rant extensively about the problems associated with using this technique. I'll keep mine short this time by keeping it to an example. From TFA in that eminent science journal Esquire:

"When you speak, blood flows to the language centers. When you blink your eyes, it flows to the eye-blinking centers."

The same region that makes something happen is also responsible for inhibiting that action. Each contains both accelerator and brakes. When you withhold speech, blood flows to the language centers. When you prevent your eyes from blinking, blood flows to the eye blinking centers. When the reaction is "I love my wife", blood flows to the I love my wife centers. When the reaction is "I don't love my wife", blood flows to the I love my wife centers.

It is not possible for fMRI to tell the difference between a positive and negative reaction, and is in fact measuring both reactions being considered prior to resolution in the sampling time. The two reactions may use some different Hebbian neural assemblies within the same region, but the low (ie. several cubic millimeters) spatial resolution of MRI catches both of them plus much more in the same voxel (3D pixel). The same problem emerges when different regions "light up" in the different conditions. It can't be determined whether that is excitatory or inhibitory activity.

By way of providing a reference, the above is what I was taught by a biophysicist who was working on his dissertation on this subject under Peter Fox, originator of the use of MRI for functional testing (ie. 'boxcar' design), including the use of SPM (statistical probability mapping) for analysis in comparing the MRI results in the different conditions. The above should also make it clear that using fMRI as a "lie detector" is fruitless.