16 May—It’s no surprise that kids’ brains are shrinking. And the National Institutes of Health (NIH) is spending $300 million to prove it. Or to disprove it, which is less likely but more politically expedient. (NIH comprises 27 separate institutes and centers, by the way, but is construed grammatically as a singular noun.)

Not all kids’ brains are shrinking, to be sure; it’s primarily the ones vegetating in kids who are glued to computer, smartphone, and television screens, as well as those who indulge heavily in what are euphemistically called substances, and, of course, those who have suffered concussion.

The NIH study is known by the clever (if not totally accurate) initialism ABCD—the Adolescent Brain Cognitive Development project. The preliminary findings were recently reported and have been panicking parents the world over. For good reason.

It appears that a number of heavy screen users among the 4,500 kids in the study showed “cortical thinning” at younger than average ages and scored lower on various aptitude tests than kids who spent less time glued to their screens.

Cortical thinning is a change in the structure of the cerebral cortex, the outer layer of the brain’s neural tissue. It plays a key role in attention, perception, awareness, thought, memory, language, and consciousness, and is the part of the brain responsible for cognition. Cortical thinning is normally associated with aging, memory loss, and other cognitive impairments.

Don’t for one minute think that the screen addicts with cortical thinning are just precocious brats. On the other hand, possible links between excessive screen time and attention deficits, mood disorders, and learning difficulties are also being investigated.

ABCD isn’t noted for its scientific rigor. One problem with it is that the study relies largely on self-reporting rather than observational data—what the brain-deficient brats (and presumably their parents) say rather than what objective observers see and record—leaving accuracy in doubt.

Another problem is that brain function is incredibly complex and as yet poorly understood. (Kind of like artificial intelligence.) So it’s difficult to generalize findings, more so since every activity the kids engage in—not just screen watching—contributes to brain development.

Neuroplasticity—the brain’s ability to be molded—is at its height during the preteen and early teen years. So, you must be wondering, is the cortical thinning permanent? ABCD will be following 11,800 kids through adolescence and conducting annual MRI (magnetic resonance imaging) scans to see.

So what about grown-up screen abusers? Don’t ask . . .