“Let me put on my thinking cap” refers to a metaphorical headpiece, though the idea makes sense — sometimes, our brains seem to slow down and have difficulty thinking, so simply uttering the phrase might prime someone to get the brain ready to focus. Now, a thinking cap is no longer a metaphor — it actually exists, and yes, putting it on can actually help you think.
Robert Reinhart and Geoffrey Woodman, psychologists from Vanderbilt, recently published a study in the Journal of Neuroscience in which they demonstrate how their thinking cap works. They specifically wanted to test the medial-frontal cortex, which, among other things, causes the emission of negative voltage right after someone makes a mistake. Scientists have never understood why this happens, but Reinhart and Woodman had a theory that it’s the brain’s way of learning from mistakes. So they set about determining the purpose of those negative brainwaves. In other words, “We wanted to reach into your brain and causally control your inner critic.” They wanted to see if it’s possible to control the brain’s reaction to making mistakes, and whether that reaction could be regulated via electrical current — specifically, the current’s directional flow.