You have a one-track mind, which is why multitasking is sabotaging your productivity

Good focus is supposed to be like a laser beam, steadily trained on a single target. For many of us, it's more like a broken disco ball spinning out-of-control. That's why we turned to Doctor Mike Dow to determine why some people find it so difficult to focus, and what we can do to improve. The bestselling author and therapist immediately started talking about multi-tasking, and the importance of doing one thing at a time.

The first point that Dow explained is that, for your brain, there is no such thing as multitasking. Subjects in one experiment were asked to perform multiple tasks while in an fMRI machine. Researchers found that the brain was not actually processing the multiple tasks in parallel, but was switching rapidly between tasks. Our brain doesn't multitask, it serially single-tasks.

With relatively simple activities, this poses no problem. Most human adults can walk down the street without losing their gum. However, as the tasks involved grow more complex, the brain takes longer to settle into each task, and the costs of switching between them rises. If we try to have a deep conversation with our partner while reading a magazine, we won't be able to follow either. If we try to text and drive, the consequences can be fatal. Psychologists estimate that, beyond the simplest of activities, task-switching can decrease our efficiency by up to 40%. As Dow puts it: "multiplication and division… lead to more lost time than addition."  When we attempt to do many things at the same time instead of a series of things one-at-a-time, we get less done.

Multi-tasking not only slows down what we are trying to do, it invites interference from things we aren't trying to do. One study examined differences between "heavy media multi-taskers" who were open to many media of communication throughout the workday, and "light multi-taskers". The study found that heavy multi-tasking reduced people's ability to distinguish between relevant and irrelevant stimuli. The more things that are happening at once, the less we can tell which one's deserve our attention and which do not. This is the logic of the internet rabbit hole, in which ever more open links lead to ever less relevant pages until we've forgotten what we were looking for in the first place.

Human beings have one-track minds, and trying to multi-task runs against our neurological nature. To improve focus and efficiency, Dow recommends accepting this fact, and making the best of it. We should attempt to do things "one-mindfully", meaning that we should try to stay entirely focused on whatever it is that we are doing until we are finished doing it.

His first tip for achieving one-mindfulness is derived from a century-old productivity method known among business writers as the "Ivy Lee Method", and among the rest of us as a "to-do list". Every night, make a list of the five to ten most important things that you must do the next day. Begin with the first ask on the list and work on it until it is finished. Move on to the next. Push any unfinished tasks to the next day.

Condescendingly obvious, perhaps. But the key is in how you understand the exercise. People tend to think of to-do lists as reminders of everything they have to do. Lists expand faster than we can tick off items, and the wall of unchecked boxes can overwhelm. Dow says this misses the point. The list is not a reminder, it's a tool for forgetting. First, it only admits the most important tasks to the list. All non-priority items are excluded. Second, it's there to store your tasks so you can put them entirely out of your mind until you finish whatever you are doing. Keep your mind on a single track until the box is ticked, and you won't lose any energy to efficiency-killing task-switches.

Dow's second tip is a classic: "know thyself". Everyone has a different attention span or capacity to focus - usually between 25 minutes and an hour - after which it becomes difficult to stay focused. Keep a note of how long you can stay on task without straying mentally. Then, set a timer. Put on your noise-cancelling headphones, put your phone on flight mode, and close all extraneous computer applications. Close your door, and focus on what you are doing and only that until the timer goes off, then take a break. Dow himself uses 45-minute increments, and says this method helped him write four popular books. He tells me that he can accomplish in 45 focused minutes what would otherwise have taken three hours.

Sometimes, even all the attention-focusing hacks in the book can't keep our minds from wandering. In these cases, it might just be that we are choosing the wrong goals. Dow told me about one patient who came to him to be treated for adult ADHD. The patient was a law student who, try as he might, could simply not concentrate on his work. After two years of therapy, the patient made an important discovery: he did not want to be an attorney. Intrinsic motivation is important, and if you are doing something you just have no interest in, you will find it hard to focus. The patient switched paths, and noticed his "symptoms" improve immediately. Dow told me that sometimes there's just no way to concentrate on work that we have no passion for. Be honest about what you can be interested in because you can't always force it.

At it's best, a wandering mind is a source of inspiration and insight, leading us to into unexplored mental terrain or shedding new light on the familiar. Newton followed a falling apple to the laws of gravity, and the taste of a tea-soaked biscuit set off a train of associations that became Proust's Remembrance of Things Past. Still, it's no way to get anything done. If you need to fight distraction and tick boxes, the best thing to do is to work within the limits of your mind, and do one thing at a time.

Clifton Mark is a former academic with more interests than make sense in academia. He writes about philosophy, psychology, politics, and pastimes. If it matters to you, his PhD is in political theory. Find him @Clifton_Mark on Twitter.