Do Phone Notifications Break Your Focus Even If You Ignore Them?

When a call or message notification reached people’s phones in the middle of a task that needed focus, they made more mistakes on the task, even though they never touched the phone. That is the result of an American experiment published in the Journal of Experimental Psychology: Human Perception and Performance in 2015.

In a Brain Mondo short video, I introduced this experiment in about 40 seconds. In this post I write about the procedure that did not fit in the video, why a notification disturbs focus, and what is known about a phone that is just sitting there.

Video: Focus facts: Phone notifications (Japanese)

The video is in Japanese.

What the experiment was

The study was done by Stothart, Mitchum and Yehnert at Florida State University. According to an article on the study from the Association for Psychological Science, the participants were 166 college students who came to the lab.

First, participants filled in a survey that included their mobile phone number. Then they worked on a task that measures how well you can keep your attention going. Numbers appear on the screen one after another, and you press a key for each one, except when the number is a 3. It is simple, but a bit mean: let your mind drift and you press the key on a 3 anyway.

Participants were randomly put into one of three groups: one that received a call notification, one that received a message notification, and one that received nothing. During the task, the researchers called or texted the participant’s own phone. Participants were not told anything about whether to check their phones, and an experimenter at the back of the room recorded how often they did.

There was a reason for using people’s own phones rather than a lab device. The researchers explain that real messages carry personally relevant content. A notification on a lab device is obviously from no one. That would not reproduce the “Who is that?” that a real notification brings on.

Result: the sound alone raised errors

Both the call group and the message group made more errors than the group with no notification. According to the APS article, people who received a notification had three times the probability of making a mistake compared with those who did not.

The paper’s abstract says that notifications alone significantly disrupted performance on an attention-demanding task, even when participants did not directly interact with a mobile device during the task.

The other important point is the size of the effect. The authors say the distraction they observed was comparable in magnitude to what is seen when people actively use a phone for calls or texting. Anyone can guess that answering a call or typing a reply breaks your focus. What this experiment showed is that you pay almost the same price at the moment the notification sounds, without doing either.

The feeling of “I’m ignoring it just fine” is not always reliable. Not reaching for the phone and not having your attention taken are two different things.

Why a notification alone does this

A notification sound or vibration is over in a moment. So why does it affect the task?

The authors’ explanation is that notifications prompt thoughts unrelated to the task, in other words mind wandering. Hear a notification and your head wanders off on its own: “Who is that?”, “Is it the reply about that thing?”, “What if it’s urgent?” The sound ends in a second, but the thoughts take a while to come back. And earlier research had already shown that this kind of mind wandering lowers task performance.

This explanation ties in with the choice of people’s own phones. A notification pulls at you because something relevant to you might be behind it. A sound from a stranger’s device would not pull your head away like that.

The video ended with “Protect your focus with your environment, not your willpower.” Once a notification has sounded, deciding “I won’t think about it” comes too late, because your thoughts have already started to drift. By the time willpower is needed, the moment has passed. That is one way to read this experiment.

What about a phone that just sits there?

Often mentioned alongside the notification research is the idea that “just having a phone on the desk lowers how well your brain works”. On this one, studies disagree.

In a study published in Scientific Reports in 2019, 132 college students aged 18 to 25 did a task of briefly holding in mind what they had seen. There were three conditions: a switched-off phone in view, a phone in silent mode in view, or a calculator in place of the phone. People higher in a tendency to act rashly when in a strongly positive mood did worse in the silent-mode condition than in the switched-off condition.

On the other hand, a study published in Consciousness and Cognition in 2020 compared having the phone on the desk with not having it there, looking at short-term memory and prospective memory (remembering to do something later). It found no overall effect of the phone’s presence. For prospective memory, only people with low smartphone dependency did better when the phone was absent. The authors conclude that the earlier finding of working memory costs from a phone’s presence does not extend to other kinds of memory.

So the effect of a phone that is just there depends on the person and on what is measured, and it is still unclear. The effect of a notification sounding, by contrast, was shown directly in an experiment with people’s own phones. So one approach is to stop notifications first and think about where to put the phone second.

What the study does and does not tell us

The participants were college students, and the task was a simple attention task in a lab. They received notifications only a limited number of times during the task. You cannot use this experiment to work out how much focus is lost in a life with dozens of notifications a day.

The same goes for driving. The authors say it is probably safest to mute or turn off your phone and put it out of sight while driving, but they did not study driving itself, and the APS article mentions a planned follow-up using a driving simulator. The study is a good reason to think about notifications while driving, but it is not data on crash risk.

Nor does the study say that everyone who gets a notification will make a mistake. What it showed is that, as a group, people who received notifications made more errors. Whether easily distracted people are hit harder, or other individual differences, cannot be seen from the abstract.

Even so, this experiment used real notifications on people’s own phones, and disruption appeared without any touching, so its conditions are close to daily life.

Using it in daily life

Here are three ways to apply this study to daily life.

• When you want to focus, stop the notifications themselves. Turning the phone face down still lets sound and vibration through. Using Do Not Disturb or a Focus mode so nothing sounds is the most reliable way.
• Put the phone out of sight. The effect of a phone just sitting there is unclear, but if it is out of sight, you will at least reach for it less. A drawer or a bag is enough.
• Decide when you will check. With notifications off, you may worry about missing something important. If you decide to check yourself once an hour, you check on your own schedule instead of being called by the phone.

Brain Mondo is a series of daily short videos about the brain, each based on a research paper. BrainDojo is an app for training calculation, memory, attention and more in a few minutes a day, and it includes training for holding and switching attention, such as counting, sorting by colour and doing two tasks at once. Try turning off notifications even for those few minutes of training, and your sense of your own focus may feel a little different.

References

• Stothart C, Mitchum A, Yehnert C. The attentional cost of receiving a cell phone notification. J Exp Psychol Hum Percept Perform. 2015;41(4):893-897.
• Canale N, Vieno A, Doro M, et al. Emotion-related impulsivity moderates the cognitive interference effect of smartphone availability on working memory. Sci Rep. 2019;9(1):18519.
• Hartmann M, Martarelli CS, Reber TP, Rothen N. Does a smartphone on the desk drain our brain? No evidence of cognitive costs due to smartphone presence in a short-term and prospective memory task. Conscious Cogn. 2020;86:103033.
• Association for Psychological Science, “You’re A Distracted Driver Even When You Ignore That Text”