“You were saying…? What happens when you ‘zone out’.”

Has anyone ever tried to get your attention because you’re blankly staring into space? Have you ever wondered why someone might be staring into nothing? Why do we do it? This odd behaviour is commonly referred to as ‘zoning out’ and relates to a lack of attention (Hamzelou, 2011). You’ve either experienced it or recognized the look on someone as you’re explaining something to them. In fact, researchers have pointed out that pupil dilation changes occur when you’re not paying attention. Pupils will either be too wide or too narrow when focus is broken, and this was found to be regardless of the time spent on a task (van den Brink, Murphy and Nieuwenhuis, 2016). But this inadvertent action might be more related to the content of the task and the performer of said task. Studying attention during reading, researchers concluded that participants who read more engaging work tended to veer off into space less than those who read more convoluted work (Smallwood, McSpadden and Schooler, 2008). Are you still with me?

Science has been trying to explain the concept of ‘zoning out’ for more than five decades. The first few studies tried to uncover why radar operators detected less targets toward the end of their shifts during WWII. As research progressed, studies uncovered that paying attention was something that actually required effort (Esterman et al., 2013). The more draining the task, the more zoning out you might do, and sometimes this even led to accidents in the workplace – as a study with pilots found in 1996 (Molloy & Parasuraman, 1996). In the past, researchers tried to understand the zoning out effect with two hypotheses: the decoupling hypothesis and the executive failure hypothesis (Kam and Handy, 2013). The former argues that the brain uses the same areas for self-reflection as for responses to external stimuli; the brain must, therefore, ‘decouple’ these areas from sensory-motor activity, in response to the outside world, to allow wandering thoughts to happen (Kam and Handy, 2013). Researchers that have shown evidence for this hypothesis have postulated that this separation occurs because the brain can recognize whether we are in danger, or in the midst of something important. And if it’s not important, we can take a break! This hypothesis supports real life situations that involve stress or fear. We do not tend to zone out during a rollercoaster ride, or during a horror movie. If it was possible to do it on purpose, I would have gladly zoned out during The Exorcist, which will haunt me forever. On the other hand, the executive failure hypothesis refutes the idea of a switchable brain, and instead proposes that zoning out is the result of the brain’s failure to sustain attention (Kam and Handy, 2013). Think of it as a saturation or ‘burn-out’ effect. The brain needs energy to focus, and if the brain is overloaded, it will stop that task. However, even if the brain is exhausted from that task, it has now taken up a musing of sorts. We’re still using our brains because our attention is diverted into something silly, like pandas, or useful, like laundry.

The advent of imaging and scanning technology has allowed researchers to focus on two domains of the brain: the default mode network (DMN), and the dorsal attention network (DAN) (Esterman et al., 2013). DMN and DAN have both been shown to ‘light up’ – so to speak – during scanning of ‘zoned out’ brains of subjects performing continuous performance tasks (Esterman et al. 2013). However, the DMN is the network that is typically linked with distraction because it is mostly active during rest periods, and it less active than DAN when attention is sustained (Esterman et al., 2013; Hamzelou, 2011). The DMN has also shown activity in resting rats and monkeys, which suggests that other animals can also zone out! Whoa! In 2013, Esterman and colleagues showed that high activity in the DMN coupled with low activity in the DAN is a signal that zoning out is happening. In other words, you will stop paying attention right at the moment when your brain is both tired and wants a break from that task. Perhaps a certain energy threshold is reached, but we will have to wait for more research to find out. Unfortunately, zoning out will also come at a cost. All of these studies have recorded errors from subjects when they are no longer focused on the task at hand. So, take a break! Remember that research has shown us that spending more time on a task might actually lead to more zoning out and more errors! Or, you can allow boredom to step in and let you use that time to brainstorm something else.

Representation of a continuous performance task. Figure from Rosenberg et al. 2013, used with permission. Individuals are asked to focus on the image and provide feedback as the images change.