So how does letting go, Lehrer asks, lead to creativity? “The story begins in the brain,” he claims, and turns to a neuroimaging experiment in which jazz pianists were asked to improvise new tunes while in a brain scanner. During improvisation, the scanner picked up a surge of activity in a brain area previously linked to self-expression. At the same time, the scientists also observed a sharp decrease in brain activity in an area previously linked to impulse control. Lehrer concludes, “This suggests that the musician was engaged in a kind of storytelling, searching for the notes that reflected her personal style…The musicians were inhibiting their inhibitions, slipping off those mental handcuffs.” At first pass, this interpretation sounds pretty convincing: the self-control center of the brain shuts down to clear the path for unfettered self-expression.
Except that it’s impossible to draw that conclusion from the data at hand. This is an example of a common logical fallacy that plagues the interpretation of neuroimaging data. Say you notice a crowd of people at your neighbor’s house one night, and then find out she is throwing a party. You can correctly conclude that whenever your neighbor throws a party, there will be people at her house. On another night, you again notice a crowd of people at her house, and you conclude she is throwing a party — but this time you’re wrong. She is hosting a church group. While you can conclude that a party means there will be people, you cannot conclude that people means a party.
. . . There is not a measurable one-to-one mapping between any brain region and any particular cognitive process; the same little patch of cortex is likely involved in multiple functions, just as a house can be filled with people for many different reasons.