Rapping in the brain scanner

In seeking to understand the brain processes underlying creative performance, researchers have already scanned opera singers and actors. Now they've invited rappers to undergo the same treatment. Siyuan Liu and her colleagues were specifically interested in the difference between freestyle rap, which requires the spontaneous generation of rhyming lyrics, and rehearsed rapping.

Twelve male professional rappers had their brains scanned while they engaged in freestyle rap and while they performed raps they'd learned earlier. Rappers usually like to gesticulate energetically as they perform, but this would have distorted the brain images so they had to keep still. No worry – "… debriefing indicated that participants' performance was not affected by the motion restraints," the researchers said. The fMRI brain scanner is effectively a powerful magnet so it would also have been imperative that the rappers remove all of their bling before the scan began.

The main finding was that freestyle rapping versus rehearsed rapping was associated with increased activation in medial (inner) areas at the front of the brain, especially on the left-hand side, and concomitant reductions in activity in dorsolateral frontal areas, especially on the right-hand side. These patterns of activation were anti-correlated – the greater the increases in left-medial areas, the more the reductions on the right lateral areas. Liu and her team think this reflects a kind of disinhibition, whereby supervisory attentional systems allowed creative areas of the brain to have free reign. The researchers said this fitted the possibility that the creative process of freestyle rap is experienced as largely occurring outside of conscious awareness. "This is is not inconsistent with the experience of many artists who describe the creative process as seemingly guided by an outside agency," they added.

Freestyle rapping also exercised language areas more powerfully than rehearsed rapping, likely indicative of the need to find appropriate rhyming words. The researchers also looked for other connectivity patterns by seeing how activity levels correlated across the brain. The medial frontal areas engaged by freestyle rap appeared to be connected to activity in prefrontal motor regions, the left amygdala and on to the right inferior frontal gyrus and inferior parietal lobes – what the researchers called a network integrating "motivation, language, emotion and motor function" and which they proposed could reflect the psychological state of "flow". Critics will likely wince at the excesses of reverse inference in this study – making assumptions about the role played by different brain areas during rapping based on the activity of those regions in other studies.

"We speculate that the neural mechanisms illustrated here could be generalised to explain the cognitive processes of other spontaneous artistic forms," the researchers concluded. Eminem was unavailable for comment.

Further reading

Liu, S., Chow, H., Xu, Y., Erkkinen, M., Swett, K., Eagle, M., Rizik-Baer, D., and Braun, A. (2012). Neural Correlates of Lyrical Improvisation: An fMRI Study of Freestyle Rap. Scientific Reports, 2 DOI: 10.1038/srep00834