There's a great piece in Seed Magazine by Paul Bloom, "Seduced by the flickering lights of the brain" (6/27/2006). Money quote:
In a recent study, Deena Skolnick, a graduate student at Yale, asked her subjects to judge different explanations of a psychological phenomenon. Some of these explanations were crafted to be awful. And people were good at noticing that they were awful—unless Skolnick inserted a few sentences of neuroscience. These were entirely irrelevant, basically stating that the phenomenon occurred in a certain part of the brain. But they did the trick: For both the novices and the experts (cognitive neuroscientists in the Yale psychology department), the presence of a bit of apparently-hard science turned bad explanations into satisfactory ones.
It's amazing how many people (including many who should know better) see functional brain imaging as "showing us directly what the brain is doing", rather than as providing yet another dependent measure, not fundamentally different in its "directness" from gaze tracking, reaction time measurements and so on.
[Update 8/10/2007: Deena Skolnick's paper came out in June 2007 in the Journal of Cognitive Neuroscience. Links and discussion are here.]
Some relevant Language Log discussion of dubious uses of neuroscience:
"Are men emotional children?" (6/24/2006)
"Maurice Saatchi, cognitive neuroscientist" (6/23/2006)
"David Brooks, cognitive neuroscientist" (6/12/2006)
"How much do those red and blue jellybeans predict about linguistic ability?" (4/17/2006)
"The brave new world of computational neurolinguistics" (12/27/2005)
"Rorschach Science" (8/12/2005)
"'The Japanese are Japanese because they speak Japanese'" (4/6/2005)
And equal time to more positively-evaluated research reports:
"Juliet was wrong" (5/19/2005)
"News about brain structure in Williams Syndrome" (425/2005)
"Structures of words vs. structures of numbers" (3/2/2005)
"Disgust for accents: pre-adaptation or figure of speech?" (8/12/2004)
"Autism as lack of neurological coordination" (7/31/2004)
"Mind-reading experiments at the University of York" (4/13/2004)
"Excitement at the Guardian about language and speech" (2/6/2004)
"Bletchley Park in the lateral interparietal cortex" (1/9/2004)