But the benefits come at a price.
“We can improve very specific think-out-of-the-box [processes], but at the same time we decrease working memory processes,” said Caroline Di Bernardi Luft, co-author of the study from Queen Mary, University of London.
Previous research by scientists in Australia found that participants who had been given small amounts of electrical stimulation were three times more likely to solve puzzles than those who had not had their brains “zapped”.
However the team behind the new study say it was not clear whether it was the suppression or the excitation of different parts of the brain that was responsible for the boost in insight.
To delve deeper, the new study tested the creative thinking of 60 participants, 47 of whom were women, using on-screen computer puzzles composed of matchsticks. The goal was for participants to move the matchsticks to produce an equation that made sense.
For example, the problem IV = III + III is solved by moving one of the matchsticks on the left to produce VI = III + III.
The problems fell into four different types, with the hardest type needing participants to override fixed ideas, such as that mathematical symbols cannot be morphed into each other by moving the matchsticks.
For example the problem III = III + III is solved by moving one matchstick from the plus sign as follows to make an equals sign: III = III = III
“They are very hard because in mathematics it is not a valid operation at all – we normally don’t decompose the plus sign, you see that as an entire entity,” said Luft.
After attempting 12 of the matchstick problems, the participants were randomly split up into three groups – and all had electrodes placed on their scalp.
While for one group the electrical current was briefly switched on and off followed by 15 minutes of no stimulation (the so-called ‘sham’ setup), the other two groups received 15 minutes of either positive or negative electrical stimulation. The non-invasive technique is known as transcranial direct current stimulation, or tDCS: negative stimulation suppresses neural activity, while positive stimulation excites it.
The current was applied to the left side of a region of the brain known as the dorsolateral prefrontal cortex – an area that is involved in functions such as planning and abstract reasoning as well as working memory – and participants were then presented with a further set of problems.
The results, published in the journal Scientific Reports, show that the proportion of participants who were able to solve the toughest problems for the first time after receiving their designated stimulation, were higher for those receiving negative stimulation at 32%, compared to just 5% for positive and sham stimulation.
That, says Luft, suggests suppression of activity in the left dorsolateral prefrontal cortex helps to override constraints in thinking learned from experience.
However the team also found that such negative stimulation resulted in participants becoming less able to tackle one of the other types of matchstick problem – suggesting that the electrical currents had impaired participants’ working memory.
Luft believes the results disrupt the notion of creativity, pointing out that the negative stimulation would not boost efforts in cases where individuals need to keep track of a number of different things at the same time. “It would be beneficial to think ‘what exactly do I need to be creative on this task’ rather than how to improve creativity in general,” she said.
Nick Davis, a psychologist and neuroscientist at Manchester Metropolitan University, who was not involved in the study, welcomed the research. “When the [dorsolateral prefrontal cortex] was ‘cooled down’, the brain seems to have stopped applying old rules, and been more successful at finding new rules – this is the essence of creativity in problem-solving,” he said of the study.
Davis adds that the new study adds weight to the idea that the technology could be exploited by consumers. “Creativity is highly prized in most areas of our lives, from work to leisure to politics and war,” he said. “Given that tDCS is commercially available and easy to build, it is possible that people may turn to tDCS for creative inspiration, in the same way that people turn to drugs or alcohol.”
Luft cautioned against the technique becoming a “home tool” but pointed out that the study also offers insights into how to boost creativity without a thinking cap. “If you are a morning person and you are working at night, your dorsolateral prefrontal cortex is going to be sub-optimal,” she said. “So you can potentially use that in your favour to try to work on specific problems that you are stuck on [as] you have a little bit less cognitive control.”
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