YaleNews: Good mental health and clear thinking depend upon our ability to store and manipulate thoughts on a sort of “mental sketch pad.” In a new study, Yale School of Medicine researchers describe the molecular basis of this ability — the hallmark of human cognition — and describe how a breakdown of the system contributes to diseases such as schizophrenia and Alzheimer’s disease.

“Insults to these highly evolved cortical circuits impair the ability to create and maintain our mental representations of the world, which is the basis of higher cognition,” said Amy Arnsten, professor of neurobiology and senior author of the paper published in the Feb. 20 issue of the journal Neuron.

High-order thinking depends upon our ability to generate mental representations in our brains without any sensory stimulation from the environment. These cognitive abilities arise from highly evolved circuits in the prefrontal cortex. Mathematical models by former Yale neurobiologist Xiao-Jing Wang, now of New York University, predicted that in order to maintain these visual representations the prefrontal cortex must rely on a family of receptors that allow for slow, steady firing of neurons. The Yale scientists show that NMDA-NR2B receptors involved in glutamate signaling regulate this neuronal firing. These receptors, studied at Yale for more than a decade, are responsible for activity of highly evolved brain circuits found especially in primates.

The disease-bias of medical research dictates that research funding is invariably going to hinge on the promise of treatment for one or more major disorders, in this case schizophrenia and Alzheimer’s. Still, in research such as that described above, it might be just as interesting and fruitful to investigate the neurological impact of what have become ubiquitous forms of behavior such as text-messaging.

In non-neurological language the use of these slow-firing neurons seems to include a constellation of cognitive activities including deliberation, reflection, analysis, and problem-solving.

Do handheld devices and the distractions they cause impair our ability to create and maintain sound mental representations of the world?

I don’t imagine Apple or anyone else with a vested interest in proving that hyper-connectivity is harmless, would welcome this line of inquiry, but still, it seems like a question worth asking.