Activation of Fusiform Face Area by Greebles Is Related to Face Similarity but Not Expertise

摘要

Some of the brain areas in the ventral temporal lobe, suchnas the fusiform face area (FFA), are critical for face perceptionnin humans, but what determines this specialization is a matternof debate. The face specificity hypothesis claims that facesnare processed in a domain-specific way. Alternatively, the expertisenhypothesis states that the FFA is specialized in processingnobjects of expertise. To disentangle these views, somenprevious experiments used an artificial class of novel objectsncalled Greebles. These experiments combined a learning andnfMRI paradigm. Given the high impact of the results in the literature,nwe replicated and further investigated this paradigm. Innour experiment, eight participants were trained for ten 1-hrnsessions at identifying Greebles. We scanned participants beforenand after training and examined responses in FFA and lateralnoccipital complex. Most importantly and in contrast tonprevious reports, we found a neural inversion effect for Greeblesnbefore training. This result suggests that people process then“novel” Greebles as faces, even before training. This predictionnwas confirmed in a postexperimental debriefing. In addition,nwe did not find an increase of the inversion effect for Greeblesnin the FFA after training. This indicates that the activity in thenFFA for Greebles does not depend on the degree of expertise acquirednwith the objects but on the interpretation of the stimuli asnface-related.