In addition to measuring Ben’s focus, we also tracked the level of arousal/excitement in Ben’s brain when he received a Slack notification. The low-interruption scenario, on the other hand, had a 3% drop in relative focus after 10 seconds. The red dot on the Slack icon was enough to see an 11% reduction in focus. Notifications in the mild-interruption scenario had a surprising impact. In all instances, Ben’s focus declined immediately after receiving a Slack notification and continued to decline afterwards:Īs expected, the high-interruption Slack notifications resulted in the largest drop in relative focus, reducing Ben’s ability to focus by 19%. Which Notifications Disrupt Focus the Most? We ran this experiment to unveil exactly what that cost is, so that we could better harness the benefits of Slack without the drawbacks.

We love Slack, and believe that it offers a ton of value–yet it comes with a cost of focus. We compared each of these against a control scenario, where the desktop Slack app was closed and no interruptions could display on their screen. Low-interruption scenario: This notification shows no red dot, but the Slack icon is permanently displayed in the dock.Mild-interruption scenario: The notification has no sound, but the Slack icon displays a red dot when there are new messages.High-interruption scenario: The Slack notification makes a sound, appears on the screen and the icon bounces in the dock with a red dot.Slack offers different settings that vary the degree of how interrupting a notification is, so we used three settings to determine how the brain reacts under different conditions: Granted, there are some things to consider here. We marked the time he received the interruption on the EEG data to see whether there were any patterns in how notifications affected his brainwaves. We hooked our designer, Ben, up to an EEG cap and while deep in focus designing the Serene app, we cruelly interrupted him with Slack messages to see what changes occurred in the brain after receiving a notification.

While there are many studies on the focus-impairing effects of mobile app notifications, there’s surprisingly little research on the impact of desktop app notifications. How Does Slack Affect Your Brain When You’re Working?

Slack phone icon