For the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh, for these are opposed to each other, to keep you from doing the things you want to do.
An impressionable mind was once thought to be reserved for the young, when fledgling brains began to spread their wings and take in the first gusts of manageable information. Now a not so new theory is gaining new currency, suggesting that our minds retain a malleability throughout life. Even the minds most seasoned by time and trial can discover new patterns no matter how entrenched their ways of thinking.
The theory is called neuroplasticity and it argues the brain is more than an astoundingly complicated computational machine. It is composed of myriad neural pathways—or “maps”—that are shaped by both our genetic and situational circumstances. The inputs we give our minds through our experiences, and the responses to them, cultivate patterns of thought that influence how we interpret and respond to subsequent stimuli.
That our minds remain impressionable is in one sense an encouraging discovery. Those who have suffered traumatic head injuries now have new hope the mind may recover significant function by training it to employ other regions to do the same task.
In another sense, though, our minds’ pliancy has doleful implications. Norman Doidge,1 a doctor and researcher in the field of neuroplasticity, has argued that exposure to pornography, for instance, does more than titillate libidinal centers—it has a lasting effect on the very structure of the brain—effects no one would sign up for if they knew what they were getting into.
1[The piece written by Doidge is taken from a compilation of essays commissioned by the Witherspoon Institute from their research project on the Social Costs of Pornography. Their findings were shared at a conference held at Princeton University in 2008. More information about the project and how to obtain copies of the papers may be found here.]
Doidge found that while pornography stimulated sexual interest in the one exposed to it, but the exposure diminished their own sexual interest for their partner. Objectification of their partner and of women in general typically followed. (Naomi Wolf’s influential piece on this same phenomenon appeared in New York Magazine as recently as 2003.)
As we’ve heard in other studies, Doidge also observed a phenomenon typically associated with narcotic substances: the effects exposure produced in time began tailing off, which then triggered the pursuit of new and more access to the material in order to obtain the same stimulation. The brain wasn’t merely receiving stimuli; it was being rewired to prompt new responses.
But perhaps most paradoxical in Doidge’s research is how pornography can increase the desire for exposure to it without a corresponding increase in the enjoyment of it. He explains how our brains have both an appetitive and satisfaction pleasure system. Pornography actuates the appetitive system, forging new pathways that increased the craving, but not always the satisfaction system that leads to a sense of peace and bliss. The brain’s plasticity means it can be shaped to want something more without at the same time liking it more. It can be seduced, if you will, to seek what does not satisfy.
We are more than brains and bodies; we have souls. Yet souls and bodies while distinct are deeply interrelated. What occurs in the brain is in part, I think, why Paul warns so strenuously of the desires of the flesh. He’s neither besmirching all things material, nor elevating the spiritual over the physical. He’s not even lambasting the things that make schoolchildren titter. Rather, he’s portending how a soul unmoored to the Spirit of God can become entangled in a seductive self-deception that is both offensive to God and toxic to body and soul. And pornography isn’t the only desire of the flesh to which we are susceptible; just see Paul’s litany in 5:19-21.
Mark underscored for us last Sunday how walking by the Spirit would be a battle. That our brains’ plasticity can allow for so much self-inflicted collateral damage is yet more evidence of the challenges associated with putting off those desires. At the same time, neuroplasticity suggests yet another reason why Paul speaks with hope that the Spirit of God can and does bring renewal to even the most poisoned.
I’m neither a neurologist, nor the son of a neurologist (though my wife sometimes affectionately refers to me as a head case). So I can’t fully evaluate the merits of the theory on neuroplasticity. But even if the neurological community provides necessary qualifications to its premises, I think we can all agree it isn’t new wisdom to say what we give ourselves shapes ourselves. Paul elsewhere calls for our minds to be renewed (Rom 12:2), in part by thinking on what is excellent (Phil 4:8), and setting our minds on things above (Col 3:1). And never far from that call to think well is the appeal to the Spirit of God to confirm what is true of Him that we might have sufficient strength to walk in what is true.
What is in need of reshaping in your soul? How might you adjust the outlay of your time and energies in this season of Lent to invite the Spirit of God to do work in what is deep in you? And in the spirit of Mark’s admonition, whom might you need to invite into the battle with you?