Solving the visual expertise mystery

Through brain imaging studies and studies of brain-lesioned patients with face or object recognition deficits, the fusiform face area (FFA) has been identified as a face-specific processing area. Recent work, however, illustrates that the FFA is also responsive to a wide variety of non-face objects if levels of discrimination and expertise are controlled. The mystery is why an expertise area, whose initial domain of expertise is presumably faces, would be recruited for these other domains. Here we show that features tuned for fine-level discrimination within one visually homogeneous class have high-variance responses across that class. This variability generalizes to other homogenous classes, providing a foothold for learning.