Regular use of smart phones and tablet devices throughout the day has become increasingly common in our tech-savvy society. The ease at which we can flick between apps for email, calendar, Facebook, Instagram, Pinterest, WhatsApp, Snapchat…, mean that we are often doing many things at once. Whether we are working or socialising, our desire to switch from one activity to the next seems to be a part of our modern multitasking culture. But are we mentally up to the task?

“Our brains are not wired to multitask well” claims Massachusetts Institute of Technology neuroscientist Earl Miller. “When people think they are multitasking they are in fact switching from one task to another very rapidly. Every time they do so there is a cognitive cost”.

Not only does the process of switching attention in the brain require additional fuel (glucose) causing us to tire faster, but it can result in an increase of both the stress hormone cortisol and adrenaline. These hormones can over-stimulate the brain and worsen our mental performance. In a study by Glen Wilson at the University of London, individuals that regularly broke away from what they were doing to answer emails or reply to text messages suffered detrimental cognitive effects comparable with a lack of sleep.

Should we just ignore the sound of a new notification on our phones until after we have finished what we are doing?

This may not be enough. Dr Wilson also found that even just the opportunity to be distracted could worsen performance. Individuals attempting to stay focused on a task whilst aware of an unread email in their inbox suffered a 10 point loss in their effective IQ. Wilson’s study was commissioned by technology firm Hewlett-Packard (HP) who stated that although technology can help productivity users must learn to switch computers and phones off. It is worth noting that this particular study was conducted in 2005 before iPhones and Android devices were even on the market. 10 years’ worth of new technology is now at our fingertips and competing for our attention like needy children.

But why are we so easily distracted?

Focussing our attention on a task is facilitated by regions of the brain that form the prefrontal cortex. When we feel good after completing a task another region of the brain, the nucleus accumbens, receives an influx of the neurotransmitter dopamine. This interaction of dopamine in the nucleus accumbens was once thought to be the cause of our pleasure sensations, but is now widely believed to be involved in forming associations between pleasure and the activity that caused it; motivating us to repeat the behaviour that led to the reward (the nucleus accumbens also appears to be involved in negative stimulus and avoidance behaviour). However there is a problem for us. The prefrontal cortex has a bias towards novel stimulus and we will often be easily distracted by something new within our environment such as a text message or a Facebook notification. When switching attention and completing this new task, the brain receives pleasurable stimulation and the nucleus accumbens once again reinforces the association between the activity and the reward. Therefore, the more we allow ourselves to break away from our main task and engage in these mini-activities the stronger these neural associations become and the more motivated we are to engage in them. Our nucleus accumbens becomes the proverbial devil on our shoulders – ‘Go, on…have a quick read of that text message’. So even though multitasking has been found to be detrimental to our performance we still feel compelled to do it. Thinking that this type of behaviour sounds familiar? That may be because the nucleus accumbens has been found to also play a role in drug and ‘junk’ food addiction. 

Is it time we took control of our tech habit?

There may be good reason to do so as a neuroimaging study by Fadel Zeidan discovered that a region of the brain known as the anterior cingulate cortex, associated with executive-level function such as staying focused on a task, was seen to be active during meditation related anxiety relief. Engaging this ‘central executive mode’ has also been shown to lower the brain’s glucose needs. Perhaps the trick to an optimal mind then is to be more Zen in the office. If a tree falls in the woods and nobody is there to Snapchat it, does it make a sound? For many of us, multitasking has become an almost inescapable part of our working lives. But just don’t expect our ancient biology to be accommodating of this. Frankly, our two hundred thousand year old brain circuitry just doesn’t care.

Richard Gardner