How often do you get interrupted during the day? Is it too often to count? And which type of disturbances have the greatest impact on your productivity?
You may have experienced a number of instances where an interruption has caused you to lose valuable time on the task at hand. One of these more major interruptions might see you not able to get back to your original work for a couple of hours; such as when being called out to deal with an irate customer, a work colleague suddenly taken ill or an unanticipated glitch in the processing of a major work document due to be delivered today. These types of interruptions whilst costly and unexpected require you to disengage from the task you were originally paying attention to and shift your focus to the new task.
Which is O.K. as far as it goes. Having a string of interruptions back to back can lead to increased irritation and frustration at not getting the work done that you had originally prioritised.
Because so many of us feel under pressure to get more done because time is valuable and appears to be in short supply, it can be very tempting to multitask.
The problem here, is that for focused attention where you have to actually concentrate on the task at hand, your brain is designed to allow to focus that attention on that one item only at a time. Trying to attend to several things simultaneously doesn’t work because it leads to your brain having to shift attention rapidly from one task to the next.
Being very obliging, your brain works very hard at this and the truth is, you are not conscious of the effort your prefrontal cortex is putting in to allow this to occur.
But it comes with a cost, a cognitive cost leading to mental exhaustion, because of the increased amount of brain energy being expended to perform this rapid task switching.
The other cost is in terms of the amount of errors made as a result. As humans, we all make mistakes, no matter how good our attention. However, having a divided attention can lead to a far greater number of errors being made and there are a number of situations where this could be critical to safety.
So how long does an interruption need to be, to be disruptive enough to cause an increased rate of errors?
The answer may surprise you.
An interruption lasting 2.8 seconds is long enough to double the potential rate of errors made.
What sort of interruptions could this include?
Well how about the thoughtless person who forgot to switch their smart phone to silent at the beginning of a presentation or meeting? You may well have experienced the annoyance of hearing the phone go off, the quick fumble in the pocket or the bag and then the second or two it takes to turn the phone off.
Or the time you are just completing an important piece of work and you are deeply engaged in it, when a colleague pops their head round the office door to ask if you want to order your lunch from the kiosk now.
The time these short interruptions matters the most is when the level of engagement or attention being paid to a particular task is especially important.
If you are a doctor undertaking a delicate procedure and concentrating hard, you don’t want an interruption from your pager or someone asking a question at the crucial moment.
Similarly, working with intricate pieces of equipment being assembled or checked in a complex piece of machinery requires concentration to ensure all the components have been accurately put together. The noise of a door slamming shut, a siren going off or a voice coming over a loud speaker are all short interruptions, but sufficient to result in an increase of error rate of up to 50%.
This finding was recently published in the Journal of Experimental Psychology: General and is one of the first studies to examine the effect of brief interruptions on relatively difficult tasks.
In the study participants were asked to perform a series of tasks in order such as identifying whether a letter was closer to the beginning or end of the alphabet using a keystroke. Being human the participants made some mistakes even when paying focused attention.
But when the participants were interrupted and requested to type two letters which took 2.8 seconds before returning to the original task they were found to make twice as many mistakes.
The learning from this is that interruptions, even when momentary can have a significant impact on efficiency and performance, which in certain situations could become critical to heath and safety.
The management of this is simple if adhered to.
If a person is required to concentrate on a particular task where it is important to minimize the risk of potential error, try to ensure that the work environment provided will have minimal interruptions. This could start with something as simple as turning off your mobile phone.
Altman, E.M., Trafton, J.G., Hambrick, D.Z. (2013) Momentary Interruptions Can Derail the Train of Thought. Journal Of Experimental Psychology: General doi: 10.1037/a003098