The left inferior frontal gyrus is activated during the processing of hierarchical structures in language, and Freidrich et al wondered whether a similar pattern would emerge when subjects processed information containing first order logic in the form of mathematics. Indeed, they found increased activation in the left inferior frontal gyrus (i.e., Broca’s area) using fMRI, but only when the subjects completed a heirarchical string as opposed during a simple list structure. Additionally of note, they found a significantly increased number of activation foci when the subjects had incorrect answers rather than correct ones, suggesting that the more uncertain answer is run through additional redunancy tests in the pursuit of error detection.
Friedrich R, Friederici AD. 2009 Mathematical Logic in the Human Brain: Syntax. PLoS ONE 4(5): e5599. doi:10.1371/journal.pone.0005599