Although “multitasking” is a popular buzzword, research shows that only 2 percent of the population actually multitasks efficiently. Most of us just shift back and forth between different tasks, a process that requires our brains to refocus time and time again — and reduces overall productivity by a whopping 40 percent.
But new research conducted at Israel’s Tel Aviv University has 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,” TAU researcher Dr. Nitzan Censor said in a statement. “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 research, conducted by TAU student Jasmine Herszage, was recently published in the scientific journal Current Biology.
Training the brain
“When we learn a new task, we have great difficulty performing it and learning something else at the same time,” Censor explains. 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,” she says.
Her 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.
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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. By utilizing the memory reactivation paradigm, the subjects were able to perform the two tasks without interference.
Uniquely pairing the brief reactivation of the original memory with the exposure to a new memory created long-term immunity to future interference, preventing the interference even a month after the exposures.
Prevention of task interference
Studies on rodents show that the “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,” she says. In other words, when a learned memory is reactivated by a brief cue or reminder, a unique time-window opens up. This presents an opportunity to interact with the memory and update it — degrade, stabilize or strengthen its underlying brain neural representations. “We utilized this knowledge to discover a mechanism that enabled long-term stabilization, and prevention of task interference in humans,” Censor said.
The researchers plan to further investigate this brain mechanism, including looking into the circuitry in the brain, functional connections between distinct brain regions, and other types of tasks and memories, beyond motor tasks.
Photos: Penn State