Although multitasking is a highly sought-after ability, many of us fail to achieve it. Rather than conducting two jobs in parallel, we flit between them, having to refocus our concentration each time we switch.
Shifting focus in this way has been shown to reduce productivity by around 40 percent, which is certainly not ideal.
It has been shown that if the human brain learns a new task and then quickly afterward learns another, the two memories “compete” and neither task is learned as efficiently; this is referred to as interference.
The two tasks demand the same brain resources, which are then split between the two tasks, significantly impairing the ability to learn either. This phenomenon can severely disrupt true multitasking.
Interfering with interference
Recently, a study was designed to investigate a potential way of negating interference and allowing two memories to stop competing and be learned more efficiently. The research was led by student Jasmine Herszage and Dr. Nitzan Censor, of Tel Aviv University’s School of Psychological Sciences and Sagol School of Neuroscience in Israel.
Specifically, the researchers examined a method referred to as “reactivating the learned memory.”
In the experiment, the participants were taught to perform a sequence of finger movements with one hand. They were required to tap out a specific string of digits that appeared on a computer screen in the shortest possible time.
Once this task had been learned, the memory was reactivated on a different day, and, as they briefly carried out the task, they were also asked to perform the same process but using the other hand.
In this instance, the participants were able to do the two tasks without interference. So, by reactivating the original memory, two distinct tasks could be carried out without the effects of interference.
Impressively, the prevention of interference lasted for 1 month after the first task had initially been learned.
Dr. Censor explains, “The second task is a model of a competing memory, as the same sequence is performed using the novel, untrained hand.” This model has previously been studied in animal models.
He continues, “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.”
“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.”
The mechanism is intriguing and has a range of real-world implications. It could also have clinical implications, potentially being of use for people who are undergoing rehabilitation following brain injuries that impact memory and motor functions.
The current study throws out many more questions, so Herszage and her team are eager to carry out more tests. They plan to dig a little deeper into the underlying brain circuitry that allows this interaction to occur. What brain regions are involved? And does the effect hold true for tasks other than motor-related ones?
As we steadily unpick the mechanisms behind reactivating a learned memory, society at large might benefit from a new ability to multitask more efficiently.