As I noted recently, in an election year like 2012, some researchers apply questionable science (partisan politicking) to the voting booth. Some of it may include widely publicized reports about brain scans purporting to show the “true” (irrational) reasons for voters’ preferences. Scans were certainly used in the 2008 US election.
Here are a few things to keep in mind, when confronting the more sophisticated manipulations we might see in a close and critical election:
1. Studies that depend on brain scans tell us far less than some claim. In “The trouble with brain scans”, psychiatrist Vaughan Bell notes, “All of our experiences and abilities rely on a distributed brain network and nothing relies on a single ‘centre.’” There is no “centre” of consciousness in the brain, no way of “reading” thoughts. A study can only tell us which brain centres are active, not why.
 2. When we find a brain area that lights up, what do we really know? In a Wall Street Journal article, “Psychology and Its Discontents”, Carol Tavris quotes Jerome Kagan in Psychology’s Ghosts:

“An adolescent’s feeling of shame because a parent is uneducated, unemployed, and alcoholic... cannot be translated into words or phrases that name only the properties of genes, proteins, neurons, neurotransmitters, hormones, receptors, and circuits without losing a substantial amount of meaning—and meaning is as fundamental to psychology as genes are to biology…”
The teen can only experience a sense of shame as a whole physical and spiritual person living in a given culture, not as one of the assorted physical components studied.
3. Hearing that brain scans validate a thesis inhibits critical thinking. In “Brain Scan Overload: Don't be fooled by pictures of the mind in action”, science writer Jonah Lehrer warns that when one researcher gave

“neuroscience students and ordinary adults a few examples of obviously flawed scientific explanations, people were consistently able to find the flaws. However, when these same explanations were prefaced with the phrase ‘Brain scans indicate,’ both the students and adults became much less critical.”
In short, publicity around brain scans can create an uncertain, gullible public, easily swayed.
4. Brain scans to discover otherwise hidden attitudes, values, and beliefs are a widely recognized failure. In “Neurononsense: Why brain sciences can’t explain the human condition”, philosopher Roger Scruton calls it a new academic disease, "neuroenvy." Disease? Yes, because

“Old disciplines that relied on critical judgment and cultural immersion could be given a scientific gloss when rebranded as ‘neuroethics,’ ‘neuroaesthetics,’ ‘neuromusicology,’ ‘neurotheology’ or ‘neuroarthistory’”.
In short, adding “neuro-” to the name of a subject does not turn it into a hard physical science.
5. New scholarly neuroscience books question simple materialist theories of mind. Raymond Tallis, Terrence Deacon, Michael Gazzaniga, and Mario Beauregard are only a few neuroscientists who have written recent books warning against the tabloid brain scan craze. As British physician and author Theodore Dalrymple puts it,

“... in my view, the neurosciences are doomed to failure, at least in their more ambitious claims. A mysterious metaphysical realm exists beyond the reach of even the most sophisticated of scanners, even if we cannot specify exactly where that realm is or how it came to be. The physiologist Moleschott, in the nineteenth century, declared that the brain secreted thought like the liver secreted bile; those neuroscientists who tell us that we are about to empty life of its mystery will come to seem as ridiculous, as absurdly presumptuous, as Moleschott seems to us now.”
To illustrate the problem, Craig Bennett and his colleagues at the University of California did a spoof experiment. The standard techniques showed “brain activity” in a dead fish. This is either evidence of life after death for fish or reason to question pop science claims about neuroscience, applied to social or political questions—and to live, vote, and believe as we feel is reasonable. Denyse O'Leary is co-author of The Spiritual Brain.