Brain scans offer a tantalizing glimpse into the mind’s mysteries, promising an almost X-ray-like vision into how we feel pain, interpret faces and wiggle fingers.
With doubts growing, many labs have become more cautious about what imaging techniques to use in efforts to unravel the average brain’s 110,000 miles (177,000 kilometers) of nerve fibers.
Yale University researcher Joy Hirsch, for example, wants to understand “the social brain” — what happens when people talk, touch or make eye contact. She’s opted out of fMRI, since it can only be used on a single person who must remain perfectly still for imagining inside a large scanner.
Instead, Hirsch uses an alternative technology that bounces laser lights off of a fiber optic cable-laced skullcap into the brain to detect blood flow. The technique, functional near infrared spectroscopy, allows her subjects to move freely during scanning and permits her to study live social interactions between several people.
