Martin Lindstrom is a branding consultant, marketing author, and (possibly because that wasn’t quite provoking enough of a violently hateful reaction in people) also apparently on a one-man mission to bring neuroscience into disrepute. He’s the genius behind the article in the New York Times in 2011 (‘You love your iPhone. Literally’) which interpreted activity in the insular cortex (one of the most commonly active areas in a very wide variety of tasks and situations) with genuine ‘love’ for iPhones. This was a stunningly disingenuous and simple-minded example of reverse inference and was universally derided by every serious commentator, and many of the more habitually rigour-phobic ones as well.
Unfortunately, it appears his reputation as a massive bull-shitting neuro-hack hasn’t quite crossed over from the neuroscience community into the mainstream, as I realised this weekend when I settled down to watch The Greatest Movie Ever Sold. Morgan Spurlock’s documentary about branding, product placement and the general weirdness of the advertising world is generally excellent, however, it unfortunately makes the mistake of wheeling on Lindstrom for a segment on neuromarketing. You can see his piece from the movie in the video below:
Lindstrom conducts a fMRI scan with Spurlock as the subject, and exposes him to a variety of advertisments in the scanner. Fair enough, so far. Then however, Lindstrom explains the results using a big-screen in his office. The results they discuss were apparently in response to a Coke commercial. According to Lindstrom the activation here shows that he was “highly engaged” with the stimulus, and furthermore was so “emotionally engaged” that the amygdala which is responsible for “fear, and the release of dopamine” responded. Lindstrom then has no problem in making a further logical leap and saying “this is addiction”.
Needless to say, I have a somewhat different interpretation. Even from the shitty low-res screenshot grabbed from the video and inserted above I can tell a few things; primarily that Lindstrom’s pants are most definitely on fire. Firstly (and least interestingly) Lindstrom uses FSL for his fMRI analysis, but is using the crappy default results display. Learning to use FSLView would look much more impressive Martin! Secondly, from the very extensive activity in the occipital lobe (and elsewhere), I’m able to pretty firmly deduce that this experiment was poorly controlled. fMRI experiments rely on the method of subtraction, meaning that you have two close-but-not-identical stimuli, and you subtract brain activity related to one from the other. As in this case, say that you’re interested in the brain response to a Coca-Cola commercial. An appropriate control stimulus might therefore be, say, a Pepsi commercial, or even better, the Coke commercial digitally manipulated to include a Pepsi bottle rather than a Coke one. Then you subtract the ‘Pepsi’ scan from the ‘Coke’ scan, and what you’re left with is brain activity that is uniquely related to Coke. All the low-level elements of the two stimuli (brightness, colour, whatever) are the same, so subtracting one from the other leaves you with zero. If you just show someone the Coke advert and compare it to a resting baseline (i.e. doing nothing, no stimulus) you’ll get massive blobs of activity in the visual cortex and a lot of other places, but these results will be non-specific and not tell you anything about Coke – the occipital lobe will respond to absolutely any visual stimulus.
By the very widespread activity evident in the brain maps above, it appears that this is exactly what Lindstrom has done here – compared the Coke advert to a resting baseline. This means the results are pretty much meaningless. I can even make a good stab at why he did it this way – because if he’d done it properly, he’d have got no results at all from a single subject. fMRI is statistically noisy, and getting reliable results from a single subject is possible, but not easy. Gaming the experiment by comparing active stimuli to nothing is one way of ensuring that you get lots of impressive-looking activation clusters, that you can then use to spin any interpretation you want.
fMRI is a marvellous, transformative technology and is currently changing the way we view ourselves and the world. Mis-use of it by opportunistic, half-educated jokers like Lindstrom impoverishes us all.