Skip to Content

Study: Smartphones Steal Our Attention and Reduce Mental Processing Speed

Study: Smartphones Steal Our Attention and Reduce Mental Processing Speed

Sharing is caring!


Smartphones are ubiquitous and have embedded themselves into every aspect of our lives. What’s the weather going to do today? Check your weather app. Need to pay your overdue credit card bill? Pay through your banking app. What are your friends doing tonight? Check your WhatsApp or Messenger group chats.

While phones are meant to make our lives easier, there is a growing body of research that suggests they may have potentially negative effects our attention spans. They don’t call it the “attention economy” for nothing!

A recent 2023 study investigated whether or not the mere presence of a smartphone in the same room, even when turned off, can influence attentional performance in college students.


The rationale for this study is that we only have so much mental bandwidth (cognitive resources) that gets divided up amongst all the different tasks we need to complete (cognitive loads). The hypothesis is that a smartphone in the same room, even if turned off, competes for and consumes our limited mental resources.


Forty two (42) students (aged 20 to 34 years, 45% female, 55% male) that completed the study were randomly assigned to two groups of 21 participants each:

  • Smartphone exposure group: Phones on the desk but kept turned off and face down.
  • Non-smartphone exposure group: Phones switched off and placed outside the testing room.

Two outcome measures were tested:

  • Attention
  • Smartphone dependence

Attention test

Attention was evaluated using the d2-r attention test which provides information about processing speed, accuracy and attention performance. It is not intended to be cognitively demanding and can be completed in under five minutes.

Smartphone dependence scale

Phone addiction was assessed by the 10-item smartphone addiction scale to reveal possible smartphone dependence (or a tendency towards smartphone dependence).


Participants in the “with smartphone” group tested significantly lower in attention performance and working speed compared to those without a smartphone, but accuracy did not differ between groups. The effect size (magnitude of difference) was large for both attention performance and speed.

In contrast to other studies which found detrimental effects on high-level complex tasks, these results suggests that, even with the smartphone turned off and face down, it can still significantly detract from comparatively simpler basal attentional processes – even WITHOUT any voluntary attention shift or active mobile phone use.


This study was conducted at-home and online due to the pandemic and could plausibly have introduced confounding effects compared to a controlled laboratory setting. But this may also have been balanced by the fact it was also carried out in participants’ own environment and might have better represented real-life multi-tasking situations.

Secondly, the participants were young German students which may limit generalisability to the broader population of smartphone users of different age groups and different cultural settings.


The findings from the present study show that even when turned off, the presence of a smartphone in the same room can still tap into and sap mental bandwidth. Leaving your phone in a different room appears to mitigate this in a sort of “out-of-sight-out-of-mind” effect.

These results also indicate the presence of a smartphone not only affects our ability to perform high-level complex tasks, but also comparatively simpler basal attentional processes.

Take home message

Smartphones only recently became mainstream over the past 10 to 15 years. While they have great potential to make our lives easier, research is now emerging that mobile phones can detract from our cognitive resources and adversely affect our moods.

These findings raise questions about whether or not smartphones are the new “digital smoking” that, for as much as we love them, they may be causing more harm than previously anticipated – check out these articles on this site on how social media affects our brains and ways to cut back on its use.

There are broader societal implications for how we should manage smartphone use in educational settings, the workplace, and in our interpersonal relationships. This research shows that taking command of our smartphones and leaving them in a different room can help us maintain and/or regain some of our mental computing power.

In the meantime, it’s up to each of us individually to reflect on our own phone use and consider to what extent it is affecting our ability to concentrate. It’s about striking a balance between getting the benefits of owning a phone while reducing the potential negative effects on our brain power.


Skowronek J, Seifert A, Lindberg S. The mere presence of a smartphone reduces basal attentional performance. Sci Rep. 2023 Jun 8;13(1):9363. doi: 10.1038/s41598-023-36256-4. PMID: 37291199; PMCID: PMC10249922.

Sharing is caring!