Research/studies Worker health and wellness Worker Health and Wellness Office Safety Tips

Within reach or not, smartphones can drain ‘brain power’: study

cellphone on office table
Photo: Rouzes/iStockphoto

Austin, TX — The presence of smartphones can significantly reduce users’ cognitive capacity – even when the devices are turned off – according to researchers from the University of Texas at Austin.

For the study, 800 smartphone users participated in a pair of trials. In the first trial, participants took a series of computer-based tests that required their full concentration to score well. They were divided into three groups, with instructions to place the phones either face down on the desk, in a pocket or bag, or in another room. In all three scenarios, the phones were turned to silent mode.


Participants whose phones were in another room scored 11.2 percent better on the tests than those whose phones were on the desk nearby, and 2.3 percent better than those who placed their phones in a pocket or bag.

“We see a linear trend that suggests that as a smartphone becomes more noticeable, participants’ available cognitive capacity decreases,” Adrian Ward, study co-author and assistant professor at UT Austin, said in a June 26 press release.

In the second trial, Ward and his colleagues tested cognitive capacity among people who said they are smartphone-dependent, defined by the researchers as “how strongly a person feels he or she needs to have a smartphone in order to get through a typical day.” Participants performed the same computer-based tests and were randomly assigned one of the three same places to keep their phones. Some were instructed to turn off their phones.

The participants who were most dependent on their smartphones performed the worst, but only when their phones were on the desk or in their pocket or bag. The researchers also found that it didn’t matter whether the phones were on or off, or if they were face down or face up on the desk – having them within sight or easy reach reduced the participants’ focus and ability to perform the tasks because part of their attention was focused on not picking up or using the phones.

“The mere presence of their smartphone was enough to reduce their cognitive capacity,” Ward said.

The study was published online April 3 in the Journal of the Association for Consumer Research.

Post a comment to this article

Safety+Health welcomes comments that promote respectful dialogue. Please stay on topic. Comments that contain personal attacks, profanity or abusive language – or those aggressively promoting products or services – will be removed. We reserve the right to determine which comments violate our comment policy. (Anonymous comments are welcome; merely skip the “name” field in the comment box. An email address is required but will not be included with your comment.)