THR Blog   /   May 12, 2016

Brain Talk in the Age of Enlightenment

A MRI machine. liz west via Flickr.

A new brain book has arrived on my doorstep, this one titled How Enlightenment Changes Your Brain: The New Science of Transformation, by Andrew Newberg, MD, and Mark Robert Waldman. The authors promise to “describe what happens in the brain as people work and move toward enlightenment” and to reveal “how the critical elements of enlightenment are reflected in different brain processes.” For this task, they explore the brain scans of psychic mediums, Sufi mystics, monks, nuns, and Pentecostals who speak in tongues. Newberg, who says he has been “mapping the neural correlates of spiritual experiences for nearly three decades,” also shares details about his own life-transforming experience and even provides functional neuroimages (fMRI) scans of his brain taken while he was contemplating “Infinite Doubt,” which is a lot of doubt. “The imaging results,” he reports, “were quite amazing.”

How Enlightenment Changes Your Brain is another installment in the burgeoning genre of “brain-training” self-help books that explore the “political,” “creative,” “loving,” “ravenous,” or just fill-in-the-blank brain. We are told that neuroscientists can explain why breaking up is hard to do, why some people are more empathetic than others, and why multitasking is actually counterproductive. Whole social categories have different brains, including teenagers, criminals, and the addicted. And now we know that they can even tell us how to gain enlightenment.

Often appearing in pairs, fMRIs seem to make the argument for difference all by themselves. Here, indicated by differently colored areas, is the “normal brain” to the left, the “ADHD brain” to the right, the “sad brain” to the left, the “happy brain” to the right, the “falling in love” brain to the left, the normal control to the right, and on it goes. To the lay reader, each image in the book is apparently a picture of the location of the brain activity which is responsible for a particular mental activity.

But such functional neuroimages show far less than we assume. Many critical discussions of the limitations of fMRIs are publicly available (you can read some here and here). But here’s the short version: fMRIs do not directly measure neural activity and what they do measure—blood oxygenation—does not always indicate an increase in neural activity. Signals in the brain occur on a far smaller and faster scale than the machine can capture, inferring a psychological process (little understood itself) from the observed brain activation is highly problematic, and the raw fMRI scans are heavily filtered by statistical processing and even Photoshopping. The published images do not represent direct observations.

Good researchers who work with fMRIs are aware of how many choices and assumptions their imaging reflects and how slight differences in empirical design can produce different results. The general public is not. We are prone to see such images more credulously: as visualizing the mind in the activities—thinking, perceiving, emoting, desiring—of the brain, more like infrared photographs than statistical constructs. The images look as though they are pictures of the brains of real people, “lighting up” in response to some task or thought. Apart from the claims made about them, if you add in the typically American reverence for science and technology, the inherent appeal and legitimacy of visual representations, and other such factors, couldn’t neuroimages have a special power to mislead?

It’s not quite so straightforward. Often cited as evidence of the power to mislead are two 2008 studies that claimed that functional brain images or explanations that began with the words “brain scans indicate” could bias lay perceptions of the quality of scientific research. But neuroscientists challenged those findings and conducted several failed efforts to replicate them. Martha Farah, a neuroscientist at the University of Pennsylvania, has written at least three articles on this theme. Her own study with Penn colleague Cayce Hook, published in the Journal of Cognitive Neuroscience, “found little evidence of neuroimagingʼs seductive allure” and, when combined with the failures to replicate the 2008 studies, “suggest that brain images are less powerful than has been argued.”

Farah and Hook sought to test whether the very presence of brain images would influence how subjects would rate a neuroscience research experiment. Their subjects were divided into three groups. Each group was presented with the same short descriptions of hypothetical but plausible research experiments. The groups differed in which type of single image accompanied the description: an fMRI scan, stock photograph, or bar chart. For each research description, subjects were asked to rate, on a five-point scale from “strongly disagree” to “strongly agree,” whether “the scientific reasoning made sense,” was “interesting” or “surprising,” and so on. The group given the accompanying fMRI image differed little from the groups given the bar charts and photographs.

Such null findings appear to show that functional brain images by themselves lack the alleged “seductive allure.” That is good news, since in the experiments the images don’t add any actual scientific information; subjects rightly inferred nothing from them. Now, there is at least one study suggesting an “allure of neuroscience” bias that makes neuroscience explanations of psychological phenomena more appealing than other types of explanation, but brain images do not independently add to this effect.

What to conclude from this? If brain images were simply passively presented in the media, as they are in these studies, we would not need to worry that we are unduly influenced by them. We would also not need to worry that they are distorting public understanding of the relation of mind and brain, especially as these play out in issues of consciousness, agency, and self, and in the arenas of health, public policy, and law.

But popular books like How Enlightenment Changes Your Brain don’t just display images; they provide interpretations of them. In these contexts, all the layers of complexity get lost and are replaced with spurious claims about the power of brain imaging to explain human differences, emotional experiences, and pathologies. We are led to believe, to quote Newberg and Waldman, that we can “see what was going on in a living brain as a person performed different activities or reflected on different ideas and beliefs.” All manner of localization claims are made—“the usual function of the parietal lobe is to take all of the sensory information coming into the brain and help us create our sense of self and establish how that self is related to the rest of the world”—and the bright colors or the arrow pointing to the brain region in the image make such claims seem true. We are not talking here about any magical powers of the images themselves but about the authority of neuroscientists to influence understanding by making unwarranted claims about what the images mean.

At issue is not just the possibility of scientific error but of philosophical error, which, unlike the former, may be much harder to correct—particularly when it becomes so widespread that people no longer realize a philosophical question is even at stake. That is the danger in all this loose brain talk. We need some enlightenment, and a serious ethical discussion about how these images are propagated and discussed is the place to begin.

Joseph E. Davis is publisher of The Hedgehog Review and co-editor of To Fix or To Heal: Patient Care, Public Health, and the Limits of Biomedicine.