By The Next List staff, CNN

(CNN) – Whether he’s peering into the mind of a mass murderer or spinning tales of the afterlife, bestselling author and neuroscientist David Eagleman is wrestling with some of the most profound questions of our existence. What is time? What is consciousness? How does the human brain construct reality?

“I’m very interested in the perceptual machinery by which we view the world,” Eagleman says, “and how we make decisions, our beliefs, our actions in the world.”

As head of the Laboratory for Perception and Action at Baylor College of Medicine in Houston, Eagleman and his students are pursuing some 50 different projects on the human brain. They study topics from time perception and brain plasticity to synesthesia, a condition characterized by a blending of senses. For research assistant and synesthete Hannah Bosley, synesthesia means that she associates letters and numbers with different colors.

“For example,” she says, “the word dog is D-O-G. It’s also yellow, clear and green to me.” FULL POST