A US study has found a person’s cognitive capacity significantly drops whenever their smartphone is within reach — even when the device is turned off.
Researchers from the University of Texas at Austin studied approximately 800 smartphone users, and sought to measure how well people could complete tasks when their smartphone was nearby, even if they weren’t actually using the device.
In the first experiment, participants sat at a computer and took a series of tests that required their full concentration in order to score well. Before the test, participants were randomly instructed to place their smartphones either on the desk face down, in their pocket or personal bag, or in another room. All phones were turned to silent.
Participants with phones in another room scored 11.2 percent better on the tests than those with their phones on the desk, and 2.3 percent better than those who had their phones in their pocket or bag.
The researchers said that even though the participants felt they were giving their full attention and focus to the task at hand, the mere presence of their smartphone reduced available cognitive capacity and impaired cognitive function.
Assistant Professor Adrian Ward said the linear trend suggested that as a smartphone becomes more noticeable, participants’ available cognitive capacity decreases.
“Your conscious mind isn’t thinking about your smartphone, but that process — the process of requiring yourself to not think about something — uses up some of your limited cognitive resources. It’s a brain drain.”
The second experiment looked at smartphone dependence. Researchers asked participants how strongly they felt they needed to have a smartphone in order to get through a typical day. Participants then performed the same series of tests under the same conditions as the first experiment.
The participants who self-reported as being the most dependent on their smartphones performed worse than their less-dependent peers, but only when they kept their smartphones on the desk or in their pocket or bag.
A key takeaway from the study was that it didn’t matter whether a person’s smartphone was turned on or off, or whether it was face up or face down on a desk. The researchers found that simply having a smartphone within sight or within reach reduced a person’s ability to focus and perform tasks because a part of their brain was actively working to not pick up or use the phone.
“It’s not that participants were distracted because they were getting notifications on their phones. The mere presence of their smartphone was enough to reduce their cognitive capacity.”