Abstract
The response to non-face objects in the face selective fusiform face area (FFA) can predict behavioral performance for these objects, but such results are often disregarded because experts may pay more attention to objects in their domain of expertise. We report an effect of expertise with objects in FFA that cannot be explained by differential attention. We relate regional cortical thickness (rCT) of FFA to face and object recognition using the Cambridge Face Memory Test (CFMT) and Vanderbilt Expertise Test (VET). Object performance in the VET was summarized using two PCA factors, one for living objects (VET-LV) and one for non-living objects (VET-NL). Using high-resolution structural data, we measured rCT in individually defined FFA1 and FFA2, OFA and PHG, in twenty-seven men recruited to vary in expertise for cars. The only significant correlations with behavioral performance were found in the FFAs. In right FFA2, rCT was positively correlated with performance on VET-NL (r=.42). This was supported by a correlation with an independent matching task with cars and planes (.43). In contrast, rCT was negatively correlated with performance on the VET-LV in left FFA1 (-.50) and FFA2 (-.68), and with performance on the CFMT in right FFA1 (-.46). Multiple regression revealed that performance with faces and objects together accounted for ~40% of the variance in rCT in several FFA patches. While men with a thicker FFA cortex performed better with non-living objects, those with a thinner FFA cortex performed better with faces and living objects. Performance with these different categories may reflect experience that is acquired during different phases of brain development (arguably faces earlier than vehicles), with different mechanisms of plasticity operating at these different times. The results point to a domain-general role of FFA in object perception, one that cannot be explained by attention to objects of expertise.
Meeting abstract presented at VSS 2015