A distraction can be defined as an urge to switch tasks.
Summary and Support
Contemporary psychological research distinguishes between two forms of attention loss: mind wandering and distraction.  In mind wandering, attention is compromised by an internal source: an inner thought or feeling temporarily captures one's interest, resulting (often unconsciously) in the redirection of attention towards that object. Distraction, on the other hand, involves an external stimulus, such as a buzzing phone, an email notification, or an object drifting across one's field of vision. In each case, a stimulus, either internal or external, threatens to sap one's attention from the task at hand.
The effects of mind wandering and distraction on productivity are closely related to the concept of multitasking. Even among the most skilled multitaskers, attention is never simultaneously focused on two tasks; rather, the prefrontal cortex rapidly alternates between the two tasks, processing chunks from each in rapid succession. The result is that attention is effectively a "limited resource": the more tasks funneled into the "bottleneck" of the prefrontal cortex, the less able the brain is manage the work at hand. Although the effect of a distraction depends greatly on its size and nature, even the smallest distraction must pass through this bottleneck, causing the brain to at least temporarily switch tasks to deal with the distraction. For larger interruptions, the brain must reorient itself to address the new task, undergoing "goal shifting" and "rule activating" phases whose time-intensiveness varies with the unfamiliarity of the task. Though these phases seem near-instantaneous, they can consume up to 40% of one's productivity in a given sitting.
A helpful way to conceptualize the above is by thinking of a distraction as an urge or invitation to switch tasks. As we have noted, even small distractions, such as an email notification, result in one's focus being momentarily redirected toward the stimulus. Larger time costs, however, are only present when the mind undergoes goal shifting and rule activating to address the stimulus, such as when one responds to the notification by opening the email application. In effective work, one seeks to eliminate both task switching and the distractions that motivate it, as both phenomena have a negative impact on the quality of one's work.
- ↑ 1.0 1.1 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6246756/
- ↑ J. Smallwood, J. W. Schooler, Psychol. Bull. 132, 946 (2006).
- ↑ 3.0 3.1 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2713348/pdf/nihms127514.pdf
- ↑ https://openpress.usask.ca/introductiontopsychology/chapter/attention/
- ↑ https://www.apa.org/research/action/multitask