Processing of featural and configural aspects of faces is lateralized in dorsolateral prefrontal cortex: a TMS study

Facial recognition relies on distinct and parallel types of processing: featural processing focuses on the individual components of a face (e.g., the shape or the size of the eyes), whereas configural (or "relational") processing considers the spatial interrelationships among the single facial components (e.g., distance of the mouth from the nose). Previous neuroimaging evidence has suggested that featural and configural processes may rely on different brain circuits. By using rTMS, here we show for the first time a double dissociation in dorsolateral prefrontal cortex for different aspects of face processing: in particular, TMS over the left middle frontal gyrus (BA8) selectively disrupted featural processing, whereas TMS over the right inferior frontal gyrus (BA44) selectively interfered with configural processing of faces. By establishing a causal link between activation in left and right prefrontal areas and different modes of face processing, our data extend previous neuroimaging evidence and may have important implications in the study of face-processing deficits, such as those manifested in prosopagnosia and autistic spectrum disorders.