From the moment we emerge into this bright, bustling world, our perceptions and experiences are inscribed on the circuits and structures of our brain. Sights, sounds, tastes, personal encounters of all sorts leave their neural imprint, stamping us as unique individuals. But arguably, it all begins with that most rudimentary of senses: touch.
“Touch is the first sense to emerge in utero, and though far from mature, it is the most strongly developed sense at birth,” writes Brooklyn, N.Y.–based science writer Lydia Denworth in our cover story, “The Social Power of Touch.”
Scientists have long been familiar with the tactile nerves that transmit pain, texture and temperature. The surprising news is that we also have nerve fibers uniquely adapted for the kind of “social touching” we do when we soothe or greet one another or cuddle a child. These fibers are calibrated for strokes that are slow and gentle (below about five millinewtons), and they are abundant in the parts of the body we instinctively pat: the shoulders and back, the top of the head. Salespeople and politicians know how to use social touch to create trust. Intriguingly, this system may be impaired in people with autism.
At the other extreme from this primal sensation is a whole new world of stimulation from modern technology. Past stories in Scientific American Mind have touched on ways that cell phones and television affect cognitive function. In this issue, journalist and former researcher Simon Makin takes a hard look at whether brain-training games—such as those offered by Lumosity—really can improve your thinking and stave off dementia.
Technology also plays a starring role in an extraordinary first-person account by Amanda Boxtel, who tells how, 18 years after becoming paralyzed in a ski accident, she learned to walk again using a robotic exoskeleton. In a companion article, “Melding Mind and Machine,” Ariel Bleicher reports on next-generation exoskeletons that will have brain-machine interfaces to communicate directly with the user's nervous system.
This is the first issue I've had the privilege of overseeing as Scientific American Mind's new managing editor. I'm eager to hear from you, our readers, about the stories you read here and those you would like to see. Find us at the e-mail address below and at that digital version of social touch—Facebook.