Think you can multitask? It’s a common theory thrown around in terms of brain performance and most people believe that they can read the paper, answer a text and perhaps workout, all the tame time. Multitasking is seen a necessary skill in our busy world, where there is often multiple stimuli coming at us all at once. The truth is that only about 2% of people are actually multitaskers.
What’s actually happening in the brain is that one task is performed, then the cognitive focus is switched to another task and perhaps then it has to go back to the original task and on and on. The brain isn’t actually doing more than one thing at a time, it’s actually switching between tasks. The problem is that while this switching over between all the important tasks is pretty cool, it actually sucks the resources of the brain. There’s one brain and when it has to perform multiple functions, switching between the two in mere seconds, the overall productivity of the brain drops by as much as 40% according to some studies.
In research completed recently at Tel Aviv University, the mechanism behind this process was examined. As it turns out, the way the brain recalls a learned memory is what blocks a person from learning something new at the same time. Precious resources in the brain are being used to call up a learned task and there isn’t enough bandwith in the brain to support learning something new at the same time. There’s only so much one brain can do.
Dr. Nitzan Censor of TAU's School of Psychological Sciences and Sagol School of Neuroscience, explained “When we learn a new task, we have great difficulty performing it and learning something else at the same time. For example, performing a motor task A (such as performing a task with one hand) can reduce performance in a second task B (such as performing a task with the other hand) conducted in close conjunction to it. This is due to interference between the two tasks, which compete for the same brain resources. Our research demonstrates that the brief reactivation of a single learned memory, in appropriate conditions, enables the long-term prevention of, or immunity to, future interference in the performance of another task performed in close conjunction.”
The team at TAU found that, much like studies in rodent models when rats were reminded of a previously learned behavior, the brief memory of the learned task opened up a “window of opportunity” for new skills to be mastered, if they were similar to the learned the memory. This ability of the brain to learn the skill, without the memory of the old skill interfering, could have implications for patients in rehab after brain trauma or those with neurodegenerative disease that impact cognition. While this isn’t multitasking, it’s still just the brain switching back and forth, it is a way to make that switching more efficient and have memories be an aid to improve learning, rather than an obstacle.
It’s a form of training the brain not to fully recall the previously learned memory of a task, but rather to use it as a brief reminder of how to learn another similar task. The researchers first taught study volunteers to tap a pattern of specific numbers onto a keyboard with one hand. Several days later, the study participants came to the lab again to learn a similar task with the opposite hand. By engaging them in a brief review of what they had already learned, but stopping short of requiring them to fully complete the original task, the brain was more receptive to learning and completing the new task. Making the brain more efficient at learning and completing new tasks, without older memories interfering, is a key mechanism for neuroscientists to understand fully. The study volunteers were able to retain this brain flexibility for as much as a month after first learning the original task, so the study could be an important first step in training the brain to be more efficient without previous memories competing for the brain resources to learn new tasks. The research, which was led by TAU student Jasmine Herszage, was published in Current Biology. Check out the video below to learn more about the myth of multitasking, how switching between too many tasks, can negatively impact the brain.