What does it take to think different? Changes in the activity of the anterior temporal lobes, if a new study has it right. Thinking the same is actually very useful, since we can use existing mental frameworks to rapidly solve typical problems. But, on occasion, we’re faced with an atypical problem, one where our past problem solving techniques don’t apply, and we need to think of a new way of doing things. At those moments, applying a small electric current to the temporal lobes might just do the trick.
Although having a toolbox of problem-solving techniques can be very valuable, the authors describe how it can make us a prisoner of our past experience. When faced with a simple task, we sometimes keep trying to use one of our existing tools, even if it’s the wrong one for the job.
To illustrate this, the authors describe a mental test where subjects are provided with simple math equations written out in matchsticks using Roman numerals (think IX – VI = III). The equations, as written, were wrong, and moving a matchstick or two was enough to set them right. For example, changing an X to a V, or a – to a + could change the math and set things straight. (My mental programmer’s toolkit would have just changed every = to a !=, but that’s apparently against the rules). People tend to find changing the numbers (called a type-1 solution) the easiest way to solve the issues, and tend to be less likely to consider changing a mathematical operator like + or altering the equality (types 2 and 3).
When subjects are trained with a set of type-1 problems, they have an unfortunate tendency when faced with a different class of problem: they can’t see past their expectations and try a different solution. Thus, they’ll perform worse on type-2 and -3 problems than someone with no training whatsoever.
Is it possible to overcome being imprisoned by our past expectations? The authors suspected that altering the anterior temporal lobes might do the trick. Historically, studies have found a left-right difference in these lobes. The left side seems to be involved in top-down reasoning and applying established mental models. The right side, in contrast, seems to be involved in processing novel situations, and updating our mental models accordingly. This left-right difference made the anterior temporal lobes prime candidates for transcranial direct current stimulation (tDCS). By passing a small current across the brain, it’s possible to stimulate neural activity near the anode, while decreasing it near the cathode. So it’s possible to use this to specifically increase the activity in the right side, which is associated with novelty.
The authors also added two control groups. One had the electrodes reversed, so the novelty-loving right side was depressed during the experiment. The second felt a bit of current as a sham, but had the tDCS device shut off before they started any problem solving. (The authors helpfully point out that “Our device is particularly reliable for blinding subjects to stimulation conditions because it can be set to an ON display even when there is no stimulation.”) All participants solved a set of type-1 problems in their training phase, and then were hit with other types of problems during the experimental portion.
What a difference a bit of current made. Only 20 percent of the unstimulated group managed to solve type-2 problems; in contrast, 60 percent of the participants who experienced tDCS managed to solve these problems. For type-3 problems, the split was 45 percent to 85 percent. The group that saw the electrodes reversed saw performance that was statistically indistinguishable from that of the unstimulated group. The authors suggest that this simply may indicate that, when faced with this test, most people are already committed to using an existing mental model.
Obviously, the authors feel that their general hypothesis—that the anterior temporal lobes help determine when we use known processes and when we get creative—is supported by the data. Because of the limits of tDCS, they can’t tell whether it was more important to stimulate someone’s creative lobe or suppress their model-drive lobe (or a combination of the two). It’s also a small study, with only about 20 people in each experimental group, but the results are so clear-cut, it’s difficult to imagine them vanishing in a larger study.
Still, the authors take the opportunity to try to link this creative problem-solving enhancement to a huge range of creative activities, from artistic abilities to paradigm-breaking scientific work. That’s almost certainly overstating their case, since those sorts of activities require efforts that are far more sustained than those involved in shifting matchsticks around.