The modern office job has made struggling jugglers of us all. Emailing, phoning, writing, accounting, project-swapping, browsing, not to mention snacking, and day-dreaming, all at once.
It helps to have the self-discipline to focus on one task at a time, but even that isn't always enough because thoughts about a previous task can linger and spoil our performance on our current task.
Now Sophie Leroy has made a counter-intuitive finding that could have implications for reducing interference between successive tasks. She's shown that completing a prior task (rather than leaving it unfinished) helps prevent its interference with a later task, but this benefit arises specifically when that initial task was completed under strict time constraints.
In an initial experiment, 84 undergrads performed a word task and then a second task based on appraising candidate CVs. The ease of the initial word task was manipulated by the researcher - one version could be completed; the other was impossible to complete. Also, time pressure was imposed on half the participants by saying that other people had struggled to succeed in the five minutes available.
Crucially, in between the two main tasks, participants performed a series of "lexical judgements" - deciding whether strings of letters were real words or not. Among the real words that were presented, some were taken from the first main task. The whole point of this was that particularly speedy performance with letter strings taken from the first task would be a sign that a person's attention was still lingering on that first task.
Leroy's first key finding was that participants who completed the initial word task under time pressure (as opposed to those who didn't complete it, or who completed it without time pressure) showed fewer signs that their attention was still stuck on the first task.
A second experiment with 78 undergrads was similar to the first, but this one looked at the effect that being mentally stuck on the first word task had on the second (CV appraisal) task. This time, participants who completed the initial word task under time pressure performed better at the subsequent CV appraisal task, than did participants who hadn't finished the first task, or who had finished it without time pressure.
Leroy further showed that participants who'd completed the first task under time pressure showed the greatest amount of confidence, when asked, that they'd fully completed the first task. Her theory is that task completion under time pressure fosters a sense of cognitive closure, allowing us to fully shift our focus onto subsequent tasks.
Leroy, S. (2009). Why is it so hard to do my work? The challenge of attention residue when switching between work tasks. Organizational Behavior and Human Decision Processes, 109 (2), 168-181 DOI: 10.1016/j.obhdp.2009.04.002