Let’s Not Overstretch Neuroplasticity
By: Maia Szalavitz
Tags: Neuroscience, Mental Health, Neuroplasticity, Science, Books

Let’s Not Overstretch Neuroplasticity

Sure, your brain is more dynamic than once thought. But harnessing those powers is tricky.

Illustration by Nick Vokey; source image by _DJ_ (CC )

Ever since researchers discovered that, contrary to prior belief, the adult brain can grow new nerve cells, neuroplasticity has been a hot topic. Conventional wisdom had previously held that the adult brain couldn’t physically change much, let alone grow new cells. In essence, neuroscientists had posited that after young adulthood, the brain’s structure was set in virtual concrete, until disease, aging, or death destroyed it.

That position never really made much sense. While learning is certainly harder as you get older, it clearly happens all the time and, thankfully, adults often do completely change their ideas and behavior. And how could it be that interaction with the environment could change your brain structurally while you are young, but never again after you reach the legal drinking age? But this is basically how the science was conveyed to the public.

Now the pendulum has swung the other way. In the last few decades there has been an explosion of books and articles to popularize the idea that the adult brain can indeed change—not just functionally, but structurally. Between 1992 and 2008, according to Google Ngram, use of the term “neuroplasticity” in books rose by a factor of eight. Many of those authors argue that the possibilities of plasticity are nearly infinite—that it can restore sight, hearing, and movement to people with disabilities or reverse brain injury, mental illness, and disease.

In The Brain’s Way of Healing, for example, psychiatrist Norman Doidge includes a series of astonishing anecdotes: a woman who healed her completely disabling chronic pain by visualizing it; a man who tamed his Parkinson’s disease with exercise; and others who overcame blindness, severe brain injury, and other profoundly impairing conditions by using non-invasive laser or electrical brain stimulation.

The stories are compelling, and the author cites studies on the individual techniques used. However, many of the patients are uncommonly driven, which matters because many of the techniques described require intense, time-consuming, long-term, and repetitive practices. The ones that don’t involve such exhausting exertions tend to use dubious technology. For example, the laser technique seemed promising at first but does not live up to its anecdotal presentation as a way to restore function in severe brain injury.

What we have here is old-time new-age nonsense in a new bottle: neuroplasticity is basically a repackaging of “mind over matter”: You, too, through sheer will or via a few lights pointed at your head, can go from being devastatingly ill to completely cured.

If we can truly understand what neuroplasticity can and can’t do — and why it’s not always good—we could gain insight into treating chronic pain and mental illness.

This is not to say that the anecdotes don’t offer hope that in some cases, the brain can repair itself. Often it can be done by intensely repeating a new behavior. Such stories are real, and such cases need to be studied. But these types of recoveries have always been seen on occasion, even when the brain was thought to be relatively rigid.

If we can truly understand what neuroplasticity can and can’t do—and why it’s not always good—we could gain insight into treating many medical problems from chronic pain to mental illness.

This sounds dicey

A slippery definition of neuroplasticity plagues Your Brain Knows More than You Think, by the psychologist Niels Birbaumer. Parts of the book are devoted, admirably, to debunking the idea that people with severe disabilities like “locked in” syndrome, who cannot communicate or move, should be assumed to have no quality of life. Birbaumer works with such patients and says many of them, once they have been taught to communicate by focusing on certain thoughts to signal intent, describe normal moods, even happiness, and do not desire to end their lives. Nonetheless, these patients are still paralyzed and have to communicate slowly and inefficiently. While neuroplasticity can allow them to learn to communicate, it certainly isn’t a cure or even restoration to health. Their brains are not demonstrating a great ability to change and recover.

Later in the book, Birbaumer tries to present evidence that a brain can unlearn psychiatric disorders like phobias and post-traumatic stress disorder. But he over-promises while promoting some ethically questionable (to say the least!) tactics.