prefrontal cortex

Shifting Gears: When your Brain needs to Pump the Clutch

December is the busiest month of the year for classical singers. It’s the peak of audition season so traveling home for the holidays is squeezed in between trips to New York or other cities for auditions. Holiday parties put friends and supporters in a festive mood, while singers juggle gigs and rehearsals and fundraising drives. Like everyone else, we pump up our productivity in this last month to squeeze a few more ounces of achievement out of the dying year. To top it all off, we actively work to avoid the illnesses that result from travel, spending more time indoors with incubating viruses and the stress of the most wonderful time of the year. If we get sick, we can’t sing, and if we can’t sing, we don’t get paid. So forgive us if we seem a little reluctant to hug and kiss each and every person at the office party.

During this month, singers aren’t the only ones mastering the juggling act. Almost everyone finds themselves multi-tasking at work and at home. By New Year’s eve, many of us feel a sense of accomplishment that comes with putting the year to bed; we’ve navigating the holiday parties and dinners, we’ve completed our gift-giving and philanthropy, we’ve finished the projects that had to be done before the turn of the year. The busyness of December pays off with one last burst of productivity.

A cautionary tale.

But there’s ample evidence, now, that multi-tasking leads to less, not more, productivity. In fact, the very idea that we can do two things at once is a myth. What we’re actually doing is switching between tasks, and every time we make a switch we pay a price. What makes multi-tasking hard? I feel the challenge most acutely when I’m trying to write something creative and/or novel and my husband interrupts me with a question or comment. My first reaction is emotional: I feel irritated. Then, I quickly realize that the idea that I was just about to make concrete has returned to its amorphous, mushy state. I refocus my attention to the question he posed, respond and shift my focus back to the last thing that I wrote. Cognitive psychologists have studied this process of ‘task-switching’ for several decades now and the ‘cost’ of switching is real in terms of response times and accuracy: we are often less accurate on switch trials than on repeated trials of the same task. One would think, though, in this age of multi-tasking, that like any other cognitive skill, practice leads to increases in efficiency.

Not so, demonstrates a study from Anthony Wagner’s lab, published in 2009. In this experiment, the Stanford scientists categorized their study participants in terms of how much multi-tasking using various media devices they were in the habit of engaging in. Heavy medial multi-taskers performed worse on a task-switching test because they were more easily distracted by irrelevant information. But as the study authors point out, there remains the question of what comes first: are heavy multi-taskers simply more distractable by nature, and thus less able to focus on one thing at a time? Or does heavy multi-tasking lead to deficits in the ability to filter out irrelevant information? Regardless of the direction of causality, one thing remains clear: multi-tasking is a hard habit to break, but one that is going to become increasingly more prevalent unless we learn to manage the addiction. And it’s worth the effort required to remain focussed.

My dear friend Karin Foerde, who is now a post-doctoral fellow at Columbia University, ran a brilliant study while we were grad students together at UCLA demonstrating that multi-tasking interferes with our ability to remember the specifics of what we were doing: instead, multi-tasking favors habit learning, which is less flexible and harder to unlearn. When you focus on one task at a time, your declarative memory system, serviced by the medial temporal lobe, is running the show. When your attention is diverted to a secondary task, the habit-learning system driven by the basal ganglia, takes center stage. Multi-tasking creates short black-outs as you switch from one task to another, inhibiting your ability to consciously remember what it was that you were doing. This year, I will be leaving my iPhone at home when I’m off to the holiday parties. Maybe that way I’ll remember just how good those Christmas cookies tasted, instead of simply wondering how those extra holiday pounds appeared on my bathroom scale.