Constant Shifts between Mental States Mark a Signature of Consciousness
Imagine driving to work along the same route you take each day. Your mind wanders from one thing to the next: the staff meeting in the afternoon, plans for the weekend, a gift you need to buy for a friend. Suddenly, a car cuts you off, and these thoughts immediately vanish—all of your attention focuses on maneuvering the steering wheel to avoid a collision. Although momentarily flustered, you—and your thoughts—return to the same wandering pattern a minute or two later.
As we go about our waking lives, our stream of consciousness typically cycles through many such alternations between introspection and outward attention throughout the day. It appears that the back-and-forth dance between these inward and outward mental states may be fundamental to brain function. A new study, led by neuroscientist Zirui Huang of the Center for Consciousness Science at the University of Michigan, suggests that the shifting balance between a network responsible for awareness of the environment and another responsible for awareness of self may be a defining feature of consciousness.