PLoS ONE 3, e1679 (2008)

Credit: B. B. HANAN

The inside of an MRI scanner may not have the ambience of a jazz club, but Charles Limb and Allen Braun of the National Institutes of Health in Bethesda, Maryland, think it brings out the process of improvisation in unprecedented detail.

They watched six professional jazz pianists first playing a scale on a specially created keyboard, and then improvising using only the notes from that scale. In a second experiment, the musicians followed a given melody exactly and then made up new trills and transitions around it. A pre-recorded quartet occasionally provided accompaniment.

When the musicians improvised, their brains showed greater activity in the medial prefrontal cortical area — a region associated with self-expression. Lateral prefrontal areas, which are linked to self-monitoring, became less active. These changes (pictured as warm and cool colours, respectively) may occur in all types of spontaneous creativity, Limb and Braun say.