This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Characterizing face representations in the ventral stream: effects of physical variability and distance from the average face fMRI research has identified regions in the human fusiform gyrus (FFA) and inferior occipital gyrus (IOG) that respond selectively to faces, but the mechanisms by which neurons in these regions represent different faces is highly debated. A prominent view posits that face-selective neurons employ a norm-based representation, responding more strongly to distinctive faces that deviate from the average face in particular directions in face space. However, in humans, evidence for this view is based on block-design fMRI experiments in which the within-block physical variability of face stimuli is not controlled across different blocks. If blocks of distinctive faces also contain more physically variable faces than blocks of typical faces, a larger BOLD response to distinctive blocks may indicate less adaptation during these high-variability blocks rather than preferential tuning to distinctive faces. To read about other projects ongoing at the Lucas Center, please visit http://rsl.stanford.edu/ (Lucas Annual Report and ISMRM 2011 Abstracts)