Every day, millions of us toggle between our electronic devices as we send email, check Facebook, watch a video clip, or respond to a text. We talk on the phone while we check Twitter and drive a car.

What could be more efficient?

Adam Gazzaley, a professor in the departments of neurology, physiology, and psychiatry at the University of California-San Francisco, has studied how the brain reacts to constant interference and distraction during multitasking. It's long been known that our brains can't really do more than one thing at a time. So what we are really doing is switching rapidly between tasks, which can cause errors and reduce productivity.

"We helped characterize what is going on in the brain, especially the aging brain, that leads to performance impairment with multitasking and when presented with distractions," Gazzaley said.

In his new book, The Distracted Mind: Ancient Brains in a High-Tech World, Gazzaley and co-author Larry D. Rosen offer practical strategies to help people use their devices in a more balanced way.

On Wednesday, Gazzaley will be at the Franklin Institute from 6:30 p.m. to 8 p.m. to discuss multitasking and how our brains really function in the digital age. He recently answered our questions about the real impact of trying to do too much.

In your new book, you say that our brains aren't built for multitasking. Can you explain?

Perhaps the most profound aspect of human brain evolution has been the development of our ability to set high-level goals. Goals that are often time-delayed, interwoven, and involve multiple individuals. Unfortunately, our chances of actually enacting these goals is restricted by limitations in our mental abilities known as cognitive control, which includes attention, working memory, task-switching, and multitasking. It is this collision between our high-level, goal-setting abilities and basic limitations in our cognitive control that creates interference, which is experienced throughout every aspect of our lives. This conflict between what we want to do, and what we can do is the basis of The Distracted Mind. Modern technology has not created this interference, but it has certainly aggravated it by offering us unprecedented access to information. In many ways we are ancient brains living in a high-tech world.

Who is affected by this problem?

Pretty much everyone. We all experience interference when we attempt to engage in more than one attention-demanding task at a time, especially in environments that are cluttered with multisensory distraction. However, it is clear that this is worse for children who are still developing cognitive control and older adults who are almost invariably experiencing a decline in these same abilities. The impact is also greater for a wide range of individuals suffering from neurological and psychiatric conditions, such as attention deficit hyperactivity disorder (ADHD), depression, post-traumatic stress disorder (PTSD), traumatic brain injury (TBI), anxiety, and dementia.

How does multitasking impact productivity?

When your attention is directed on a specific task, a brain network is selectively engaged to focus your limited mental resources on accomplishing your goal. If you then decide to do something else at the same time; for example, take a phone call while answering your emails, the brain network is disrupted and re-engaged as a new network to focus your attention on the other task. We are not capable of simultaneously engaging more than one network if it demands attention, and so our brain switches between the networks. With each switch there is a cost in performance, which may present itself as being slowing or with diminished accuracy.

Do people who multitask experience any other problems from the practice?

There is research that shows people who multitask a lot with media tend to perform poorly on tasks of cognitive control (working memory, attention, distraction resistance) when tested in a laboratory. However, this data does not inform us that this was the result of them multitasking too much. It could be that people who tend to multitask a lot have worse cognitive control abilities to begin with. There is also data suggesting an impact on happiness, stress, and anxiety.

How we can learn to train our brains to be stronger and more resilient to disruption?

In the book, we explore a whole array of potentially powerful ways to enhance your cognitive control abilities and diminish the impact of a distracted mind: cognitive training, video games, pharmaceuticals, physical exercise, meditation, nature exposure, neurofeedback, and brain stimulation. But although there is some evidence for these approaches being effective, we need to do a lot more research across the board. We also discuss ways that you can modify your behavior, without abandoning modern technology, to minimize negative consequences of interference, such as decreasing accessibility to tech at certain times and better managing boredom and anxiety.