Brain Imaging: One Way In
A non-invasive and relatively safe way to peek into the live workings of the brain.
If anything has been the rage recently among technophiles and those who follow popular science trends, it's human brain imaging. A search on the PubMed database returns over 11,000 studies with "functional magnetic resonance imaging" (fMRI for short) in the title or abstract—and those results only apply to the last decade. Compare that to only about 1,000 studies with "fMRI" in the abstract or title in the 1990s! In a recent article published in Current Opinion in Neurobiology, cognitive neuroscientist Russell Poldrack of UCLA says that 30-40 new brain imaging papers are published on a weekly basis—a high rate. There's no doubt that brain imaging is here, and here to stay.
As fMRI becomes a pervasive force in scientific research, it is also gaining popular interest as a window into the brain and the way humans work. Its widespread adoption has serious implications for the way people think about their own brains. Like all technologies, we must understand fMRI's proper use in order to rightly interpret its findings.
Unlike standard MRI, which takes a static picture of the brain, fMRI measures neural activity over time, showing the brain in action. (For an informative overview of how fMRI works, see howstuffworks.com.) Key to this technology is its use of the way active neurons consume energy: they require more oxygen to function than inactive neurons, creating different levels of oxygenated blood. An fMRI scanner essentially takes the ratio of oxygenated blood (indicating active neurons) to deoxygenated blood (indicating inactive neurons that haven't consumed energy). As this ratio is computed across different areas of the brain, the computer attached to the fMRI scanner converts all the numeric data into a comprehensive, coherent image.
fMRI is incredibly useful, primarily because it presents researchers with a non-invasive and relatively safe way to peek into the live workings of the brain. Since fMRI came on the scene in the early to mid 1990s, psychologists and neuroscientists have developed a much richer picture of how the brain functions in the normal (non-clinical) population, and major breakthroughs have occurred in understanding the neural basis in neurological and psychiatric disorders.
For instance, in 1999, British psychologist Simon Baron-Cohen and colleagues used fMRI to demonstrate that autistic patients had starkly different patterns of brain activation during a Theory of Mind task, which involved inferring others' mental states upon viewing emotional facial expressions. Significantly, autistic patients were impaired in the Theory of Mind task, suggesting that the social deficits of autism might be grounded in abnormal neural activity. This study, published in European Journal of Neuroscience, launched a flurry of autism research that considered the relative causal roles of genetics and environment in the disorder's pathogenesis. The study used brain imaging not as an end to itself, but as a tool to understand neural functioning—with the ultimate goal of bringing intervention and healing to those suffering from psychological dis-ease and disorder.
The potential problem with brain imaging is not the technology itself, but the way in which brain imaging findings are readily (and sometimes hastily) disseminated through the media. When a study incorporating brain imaging techniques is published in a top-tier journal, the popular media often jumps on the opportunity to report on the findings. And, sadly, the reporting is rarely measured. Rather, it's often careless, accompanied by sweeping statements that at best over-generalize a study's findings, or at worst sensationalize and distort the data.
But it's one thing for a journalist, unfamiliar with brain imaging technology and its limitations, to exaggerate a study's findings. It's another thing entirely for researchers to take advantage of media outlets to push an agenda that's not necessarily supported by their data—exactly what happened in November 2007. Several neuroscience researchers wrote an op-ed in The New York Times entitled "This Is Your Brain on Politics," in which they made claims about what participants were feeling—anxiety, disgust and so on—as participants viewed politically-charged stimuli, like the words Democrat, Republican or independent. The researchers used the brain data to infer political preferences, using one-to-one mappings of the amygdala, the region of the brain which processes emotion and affective value, to an emotion or feeling. But such simple "If this brain region, then this psychological process" kind of reasoning is not warranted by brain data alone, as was well argued by a group of concerned cognitive neuroscientists in a letter to the editor published several days after the op-ed piece appeared.
So, with both the merits and limitations about brain imaging in mind, and with the knowledge that great gifts mean great responsibilities (Luke 12:48), what do we make of this technology?
We first must take a posture of gratitude, specifically for the unprecedented innovation of magnetic resonance imaging, which allows man-made materials and devices to intelligibly interpret the organic electrochemical workings of the brain. Humanity as a whole rightly expressed this gratitude when the 2003 Nobel Prize in Physiology or Medicine was awarded to the developers of magnetic resonance imaging.
We should also share measured optimism about how far brain imaging can go and what it can help us explain. It is easy to fall into the equally tempting traps of debilitating skepticism or unchecked devotion to the technology's promise. To avoid both of these, we must revisit our presuppositions about what makes us human. If the human experience (especially its moral and spiritual dimensions) is greater than the sum of its raw, biochemical parts, then brain imaging technology is necessarily limited by design to capture the rich phenomenological landscape of human experience. And if we accept this, then it follows that brain imaging should be supplemented by other empirical and non-empirical tools to help us get closer to understanding our en-fleshed minds.
Brain imaging technology is a powerful gift, a gracious gift from God to humanity. But it gives us only one window into our complex, ever-changing mental lives. We should hope that humanity will be given more windows and ways into our brains—insofar as we long to better know and love each other and our Creator.