Abstract
Previous work has established that visual processing in expert radiologists differs from processing in non-experts. To better understand the mechanisms of this expertise we used functional magnetic resonance imaging (fMRI) to compare neural activity in expert thoracic radiologists and beginning radiology residents as they detected abnormalities in chest radiographs. Subjects viewed intact and scrambled chest radiographs and indicated whether a lung nodule was present in a cued region of the image while BOLD fMRI data were acquired using a rapid event-related design. For each subject, regions of interest—V1, V2, V3, lateral occipital complex (LOC), fusiform face area (FFA), and radiograph-selective regions—were defined using separate localizer scans. Average event-related responses were computed using ordinary least squares from the fMRI time course averaged within each region. In experts regions in lateral occipital cortex showed higher fMRI response amplitudes for intact compared to scrambled radiographs. These radiograph-selective regions were not coincident with the FFA and were weaker or absent in residents.