Normal sensitivity to facial identity in right anterior inferotemporal face-selective region in the absence of right fusiform face area

摘要

Multiple face-selective cortical regions have been identified in humans, but the function of each region and the relationship between them remains unclear. We addressed this issue by examining the effect of a lesion to a posterior region in the face network on the functioning of a more anterior region. Galen is a 30-year-old right-handed male who became prosopagnosic after a surgery to remove a cerebral arteriovenous malformation (AVM) in his right occipito-temporal cortex. A structural scan revealed lesions on the right side extending from the temporal lobe to the occipital lobe, as well as a small part of right cerebellum. A localizer scan showed that Galena??s right fusiform face area (FFA) was missing due to the lesion. Other face-selective areas were present including bilateral occipital face area (OFA), bilateral posterior superior temporal sulcus (pSTS), bilateral anterior STS (aSTS), and left FFA. Most importantly for the current study, bilateral regions in Galena??s anterior inferotemporal cortex (aIT) also showed a face-selective response. We used fMRI-adaptation to investigate the sensitivity of Galena??s aIT to facial identity. On each trial, two different images of the same celebrity or two different celebrities (age- and sex-matched) were presented. In the scanner, Galen and nine control participants judged whether pairs of images showed the same celebrity, and as expected, Galena??s discrimination ability was significantly worse than the controls. The control group showed significant repetition suppression for the same identity pairs in right aIT. Surprisingly, Galena??s right aIT showed repetition suppression comparable to that seen in the controls. This finding demonstrates that the right aIT can preserve its face-selectivity and continue to represent identity information despite of the loss of the right FFA.