Scientists find that attention cuts through brain 'noise' that impairs visual perception
Source: Salk Institute
The ability of the brain to ignore extraneous visual information is critical to how we work and function, but the processes governing perception and attention are not fully understood.
Scientists have long theorized that attention to a particular object can alter perception by amplifying certain neuronal activity and suppressing the activity of other neurons (brain ''noise'')
Now, scientists have confirmed this theory by showing how too much background noise from neurons can interrupt focused attention and cause the brain to struggle to perceive objects.
To test this idea directly, the researchers turned to a cutting-edge technology called optogenetics, a technique that can affect the activity of neurons by shining lasers onto light-activated proteins.
The team used a low-frequency laser stimulation protocol directed at a visual brain region in animals to create low-frequency response fluctuations, the very neural fluctuations that attention suppresses.
They measured the impact of this on the animal's ability to detect a small change in the orientation of a visual stimulus presented on a computer screen. As predicted by the theory, the added noise impaired perception.
Then, they repeated the experiment, but using a different laser protocol to induce fluctuations over a high-frequency range that attention does not suppress. Consistent with the theory, this had no impact on perception.