For the love of God...

The August edition of Neuroscience Letters included work by Mario Beauregard and Vincent Paquette that examined whether a “God Spot” could be found in the brain.  Not surprisingly, the paper generated quite a buzz (see here, here and here for various accounts). From the text:

The main goal of this functional magnetic resonance imaging study was to identify the neural correlates of a mystical experience (as understood in a Christian sense) in a group of Carmelite nuns. 

Here are the details of their design:

BOLD signal changes were measured during a Mystical condition, a Control condition, and a Baseline condition. In the Mystical condition, subjects were asked to remember and relive (eyes closed) the most intense mystical experience ever felt in their lives as a member of the Carmelite Order…In the Control condition, subjects were instructed to remember and relive (eyes closed) the most intense state of union with another human ever felt in their lives while being affiliated with the Carmelite order.

Here are the summarized results:

[The Mystical condition] was associated with significant loci of activation in the right medial orbitofrontal cortex, right middle temporal cortex, right inferior and superior parietal lobules, right caudate, left medial prefrontal cortex, left anterior cingulate cortex, left inferior parietal lobule, left insula, left caudate, and left brainstem. Other loci of activation were seen in the extra-striate visual cortex.

So although the study does not support the existence of a “God spot,” it does provide evidence that humans may be wired with a “God network.”

The recent issue of Psychiatry Research: Neuroimaging includes a paper that takes a different approach to the same question. In this experiment, SPECT was used instead of fMRI. Also, the subjects weren’t nuns asked to imagine an experience; they were self-proclaimed Christian women who practice glossolalia. For those who aren’t familiar with glossolalia, check out this movie. Or just read the paper’s abstract:

Glossolalia (or “speaking in tongues”) is an unusual mental state that has great personal and religious meaning. Glossolalia is experienced as a normal and expected behavior in religious prayer groups in which the individual appears to be speaking in an incomprehensible language. This is the first functional neuroimaging study to demonstrate changes in cerebral activity during glossolalia. The frontal lobes, parietal lobes, and left caudate were most affected.

A subscription is required to view the full text of the article, but here is a summary. Also, see the Neurocritic for deeper perspective and other informative links. Like the previous paper, this one also suggests that evidence points to a “God network,” but not a “God spot.”

But should such a definitive conclusion really be drawn? Consider the following fundamental rule of experimentation: to measure a variable’s effect across treatments, everything except this variable must be held constant. If a design’s treatments differ in multiple ways, a given change cannot be attributed to a particular variable of interest. Thus, in order for these studies to isolate the effect of a religious experience, other effects must be controlled for.

The researchers who scanned the nuns anticipated this issue. Following the image acquisition, an item on a self-report questionnaire asked the nuns to rate the level of intensity that they felt when imagining the religious and non-religious experiences in the scanner. Because there was no significant difference between religious ratings and non-religious ratings, one can plausibly conclude that the “intensity effect” was controlled for.

But other variables besides intensity may be at work. Consider that the nuns in the control phase were simply asked to imagine an intense interaction with “another human.” Given this feature of the design, the results imply that the imaging data associated with an imagined interaction with God is different that the data associated with an imagined interaction with anther human. But what if the other human was instead one’s child or significant other? (Don’t let the fact that nuns aren’t likely to have children or significant others interfere with the thought experiment.) The results cannot shed any light on whether the neural response generated when someone thinks about God is significantly different than the response generated when someone thinks about an individual near and dear to her heart.

In a similar vein, consider that the control phase in the glossolalia experiment involved women singing along with a recorded religious song. Therefore, the design allows one to conclude that the response to glossolalia is different than the response to singing a religious song that someone else created. As another thought experiment, consider the extent to which the results might be different if the control phase involved someone singing her own song. Perhaps a song-writer’s sense of ownership and/or profound attachment to the words that she sings generates a neural response that does not significantly differ from that which is observed during glossolalia.

In truth, child-rearing nuns (with or without husbands) and song-writing glossolalia practitioners hardly form effective sample sizes. But the theoretical examples highlight an important practical issue: before anyone can use experiments to demonstrate that there is “something about God,” innovative techniques must bridge the gap between the spiritual and the mundane. Until they do, there is simply no way to know whether the brain’s response to a religious experience is quantitatively different than its response to any of the deeply meaningful stimuli that surround our daily lives.