University of Texas researchers asked study participants to take a series of tests to measure their available cognitive capacity — that is, the brain’s ability to hold and process data at any given time. Participants randomly placed their smartphones (in silent mode) either on the desk, in their pocket or personal bag, or in another room.
The participants who left their phones in another room significantly outperformed those who had placed the phones on the desk, and these in turn slightly outperformed participants who had their phone in a pocket or bag. The results suggest that the mere presence of the devices is enough to drain somebody’s mental resources and impair cognitive capacity, even though participants felt that they were completely immersed in the task.
“Your conscious mind isn’t thinking about your smartphone, but that process of requiring yourself to not think about something uses up some of your limited cognitive resources. It’s a brain drain,” says assistant professor Adrian Ward.
Whether the phone was turned on or off didn’t seem to matter, nor if it is on the desk lying face up or face down — all that was needed to reduce a participant’s ability to focus was to have a smartphone within reach.
The researchers say it doesn’t come down to us delegating some cognitive processes over to the devices and losing on brain ‘exercise’; rather, it’s a matter of self-control. We’ve become so attached to smartphones that the brain actually has to give up part of its processing power to keep the urge of picking them up at bay.