Controlling brain waves to stay visually aware
Researchers at Beckman Institute have used a novel technique to determine how the brain processes external stimuli that reach (or don’t reach) our awareness. “When we have different things competing for our attention, we can only be aware of so much of what we see,” said Kyle Mathewson, Beckman Institute Postdoctoral Fellow.
“For example, when you’re driving, you might … see something brief or faint while you’re paying attention to something else, so the event [such as a truck heading at you] won’t come into your awareness.
“If you present this scenario hundreds of times to someone, sometimes they will see the unexpected event, and sometimes they won’t, because their brain is in a different preparation state.”
Mathewson and colleagues are finding out how the brain does this by using a novel technique to test brain waves. Surprisingly, they found that alpha waves, typically only thought of the brain’s electrical activity while it’s at rest, can actually inhibit what is processed visually, making it hard to see something unexpected.