Mind monitor shows alpha level selections
As we move through our daily lives we may think we are fully aware of our surrounds, but there is plenty of information that the brain takes in but never brings to our full attention.
Using new technologies to monitor brainwaves in real-time, researchers are discovering just how the brain processes external stimuli that do and don’t reach our awareness.
The study reveals how alpha waves - the brain’s electrical activity while at rest - can actually influence what a person does or does not see.
Researchers used both electroencephalography (EEG) and the event-related optical signal (EROS), developed in the Cognitive Neuroimaging Laboratory of Gabriele Gratton and Monica Fabiani, professors of psychology, neuroscience, and authors of the new study.
While EEG records the electrical activity along the scalp, EROS uses infrared light to measure changes in optical properties in the active areas of the cerebral cortex.
Because of the hard skull between the EEG sensors and the brain, it can be difficult to find exactly where signals are produced. EROS, which examines how light is scattered, can help pinpoint activity within the brain.
The combination allowed the researchers to not only measure activity in the brain, but also allowed them to map where the alpha oscillations were originating.
Excitingly, they discovered that alpha waves are produced in the cuneus, located in the part of the brain that processes visual information.
The alpha waves can inhibit what is processed visually, making it harder to see something unexpected.
By focusing attention and concentrating more fully on conscious experience, the team says that the executive function of the brain can come into play and provide “top-down” control—putting a brake on the alpha waves, and allowing a person to see things that might have been missed in a more relaxed state.
“We found that the same brain regions known to control our attention are involved in suppressing the alpha waves and improving our ability to detect hard-to-see targets,” said Diane Beck, one of the study’s authors.
“Knowing where the waves originate means we can target that area specifically with electrical stimulation” said researcher Kyle Mathewson.
“Or we can also give people moment-to-moment feedback, which could be used to alert drivers that they are not paying attention and should increase their focus on the road ahead, or in other situations alert students in a classroom that they need to focus more, or athletes, or pilots and equipment operators.”
The lab put together the following video to explain their work;