Thinking that the task you are doing involves multitasking rather than a single tasking activity can increase your engagement and effort, and subsequently, task performance (Srna, Schrift and Zauberman, 2018).
In an experiment, people were divided into two groups. Group One was presented with two puzzles side by side on the same page. They were told that the two puzzles were required for two different experiments. The two puzzles were separated by a vertical line in the middle, and had two different background colours to make the puzzles seem like two separate tasks. The aim was to make the Group One to feel like they were multitasking. Group Two was also presented with the same two puzzles but they were told that they were required for a single experiment. The two puzzles were not separated by a vertical line and both had the same background colour in order to make them feel like they are working on a single task.
Group One that was made to feel like they were multitasking performed better and longer than Group Two that was made to feel like they were completing a single task.
We can apply this whenever we are working on a task. For example, when you are writing a report, you can think of it as doing a single task of writing a report or as doing multiple tasks including reading, summarising, brainstorming, structuring arguments etc. This perception that you are indeed multitasking enables you to focus more on the task and achieve better outcomes.
Tricking your mind that the task you are performing involves multitasking can help increase your focus and effort on the task.
Srna, Shalena, Rom Y. Schrift, and Gal Zauberman. "The illusion of multitasking and its positive effect on performance." Psychological Science 29, no. 12 (2018): 1942-1955.