In this study, we ask whether or not the involuntary capture of attention by a specific information type can produce domain-specific activation. Participants indicated the presence of a flicker in rapidly alternating letter-string masks presented in the periphery. Despite letters not being relevant to the task, we found, using functional MRI and a novel task that allowed us to contrast attended and unattended processing of the same visual information, a robust modulation by attentional capture in a localized letter-processing region.