Fluctuations of fMRI activation patterns in visual object priming

Abstract

Prior information shapes how the brain processes sensory inputs (e.g., priming effects). Recent studies of "behavioral oscillation” have demonstrated that the effects of visual object primes are temporally coordinated in the theta band to guide perception efficiently. However, the neural mechanism underlying this dynamic processing remains unclear. Here, we combine functional magnetic resonance imaging (fMRI) and a time-resolved paradigm to access high-temporal-resolution profiles of brain activation fluctuations corresponding to "behavioral oscillation" in visual object priming. Specifically, multivoxel activity patterns in the fusiform face area (FFA) and the parahippocampal place area (PPA) show temporal fluctuations in the theta band (~ 5 Hz). Importantly, the theta-band power in the FFA negatively correlates with reaction time, further indicating the critical role of the observed fluctuations in brain activation. By finely mapping the temporal dynamics of cortical responses, our fMRI results demonstrate that category-selective brain areas underlie the rhythmic coordination of visual object processing.