Researchers in Germany have found that the brain does indeed power up and start running whenever it hears the ringtone you've associated with your ever-present phone. Change your ringtone to something very unique, then, to avoid accidental anxiety and interruption.
Photo by loudestnoise.
Many students who took a basic psychology class will know the brain already has a "Cocktail Party Effect" working at most times, which lets the brain focus in on any conversation in which, say, one's own name comes up. The same goes for the ringtone you've associated with your own phone — even when pressed and trained to focus on a different ringtone, study participants' brains were running more actively after hearing their own, familiar ringtone.
What can you take away from this little bit of science? For one thing, as noted by many Gizmodo commenters, it might be smart to make your ringtone very unique. Using your carrier or phone model's default, or a commonly heard song, can trigger inadvertent "Oh-my-goodness-my-phone-my-phone" moments in public or at the office. So the next time you're messing with your ringtones, consider it more psychological long-term investment then short-term procrastination.