Although some people – especially busy women – are thought to be good multitaskers, in fact only about 2% of the population actually does several things at once efficiently, according to researchers at Tel Aviv University.Most of us just shift back and forth among different tasks, a process that requires our brains to refocus time and time again and reduces overall productivity by a whopping 40%.Dr. Nitzan Censor of TAU’s School of Psychological Sciences and the Sagol School of Neuroscience, with student Jasmine Herszage, recently published their study in Current Biology.They identified a brain mechanism that enables more efficient multitasking.The key to this is “reactivating the learned memory,” a process that allows a person to more efficiently learn or engage in two tasks in close conjunction.“The mechanism may have far-reaching implications for the improvement of learning and memory functions in daily life,” Censor said. “It also has clinical implications.It may support rehabilitation efforts following brain traumas that impact the motor and memory functions of patients, for example.” The brief reactivation of a learned memory can block interference from competing tasks. “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 doing it with one hand) can reduce performance in a second task B (such as performing it 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,” he explained.“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 TAU scientist said.The researchers first taught student volunteers to perform a sequence of motor finger movements with one hand, by learning to tap onto a keypad a specific string of digits appearing on a computer screen as quickly and accurately as possible. After acquiring this learned motor memory, the memory was reactivated on a different day, during which the participants were required to briefly engage with the task – this time with an addition of brief exposure to the same motor task performed with their other hand. The subjects were thus able to perform the two tasks without interference.By uniquely pairing the brief reactivation of the original memory with the exposure to a new memory, longterm immunity to future interference was created, demonstrating a prevention of interference even a month after the exposures, he said.“The second task is a model of a competing memory, as the same sequence is performed using the novel, untrained hand,” said Censor.“Existing research from studies on rodents showed that a reactivation of the memory of fear opened up a window of several hours in which the brain was susceptible to modifications – in which to modify memory.”This presents an opportunity to “interact with the memory and update it – degrade, stabilize or strengthen its underlying brain neural representations,” creating a mechanism that made possible long-term stabilization and prevention of task interference in humans, he concluded.