Keio Research Highlights

Electrically stimulating certain pleasure-sensing regions of the brain can change a person's subjective experience of beauty, researchers at Keio University have discovered¹.

In a study of 47 female Japanese students, researchers found participants whose medial prefrontal cortex was inhibited with an electrical current were significantly less likely to find beauty in a series of 20th century abstract artworks. However, the stimulation had no effect on their experience of ugliness, supporting the idea that beauty and ugliness are not opposite ends of the same scale but independent subjective experiences.

"This can help us understand the conflicting experience elicited by recent works of modern art, in which there is beauty and ugliness together in a single art work," says Hideaki Kawabata from Keio's Department of Psychology, who led the study.

In previous studies using brain imaging machines, Kawabata and his colleagues showed that the medial prefrontal cortex is activated when a person sees a face, painting or even mathematical formula they consider to be beautiful. "This brain area also responds when we observe good, moral or social behaviors in others," Kawabata adds.

Ugliness, in contrast, lit up the left motor cortex of the brain, a region whose primary function is to plan and execute movement ― suggesting it primes neural circuits to "escape from aversive stimuli or situations, or flick away incoming aversive objects," Kawabata says.

Kawabata and his team investigated the human experience of beauty and ugliness in more detail using a brain stimulation technique called transcranial direct current stimulation (tDCS). tDCS involves placing electrodes at certain positions on the scalp, to either enhance or suppress brain activity in areas beneath the electrode.

Although enhancing activity in the medial prefrontal cortex had no effect on participants' experience of beauty or ugliness, suppressing activity in the brain region made them less likely to find abstract paintings beautiful.

The results surprised Kawabata because they suggested that the medial prefrontal cortex is not just responding to the feeling of beauty ― it actually has a role in causing the feeling.

In contrast, stimulating or inhibiting the medial prefrontal cortex had no effect on the number of paintings participants considered ugly, confirming that ugliness is not the opposite of beauty, but must arise as a separate cognitive mechanism in a different part of the brain.

The team plans to test whether, by adjusting the placement of electrodes, it is possible to enhance people's perception of beauty. Kawabata also raised the ethical dimension of being able to manipulate a person's subjective experiences using brain stimulation.

1. Nakamura, K. and Kawabata, H. Transcranial direct current stimulation over the medial prefrontal cortex and left primary motor cortex (mPFC-lPMC) affects subjective beauty but not ugliness. Frontiers in Human Neuroscience 9, 654 (2015). | article