Early monocular enucleation selectively disrupts the development of neural mechanisms for face perception
41.12, Monday, 19-May, 8:15 am - 9:45 am, Talk Room 1
Krista Kelly1,2,3, Keyvan Tcherassen1, Brenda Gallie3, Jennifer Steeves1,2,3; 1Department of Psychology, York University, Toronto, ON, Canada, 2Centre for Vision Research, York University, Toronto, ON, Canada, 3The Hospital for Sick Children, Toronto, ON, Canada
Background. Monocular enucleation (surgical removal of one eye) during infancy results in intact low- to mid-level spatial vision (see Kelly et al., 2013 for a review). A mild impairment is observed, however, for the higher-level spatial vision ability, face perception, compared to binocularly intact controls (Kelly et al., 2012). Nonetheless, house perception is intact, suggesting a face-specific deficit with early enucleation. Similar face deficits are observed in monocular deprivation from congenital cataract (Le Grand et al., 2003, 2004). Further, early monocular deprivation from amblyopia and strabismus decreases functional activation in face-selective brain regions, including the middle fusiform gyrus [fusiform face area (FFA)] and inferior occipital gyrus [occipital face area (OFA)] (Lerner et al., 2003, 2006). Here, we sought to determine if decreased functional activation in face-specific brain regions are also present following early monocular enucleation. Methods. Six adults who had one eye enucleated early in life due to retinoblastoma (cancer of the retina) were compared to eight age- and sex-matched binocular and monocular viewing controls. All participants were placed in a 3T scanner and viewed blocks of images of faces, places, and objects. Repetition detection was used to maintain attention. Whole brain analyses were conducted to locate face-selective regions (FFA, OFA), and place-selective regions [parrahippocampal region (PPA), transverse occipital sulcus (TOS)] were used as a control comparison. Results. The early monocular enucleation group exhibited reduced activation in face-selective, but not place-selective, regions compared to controls. Conclusions. Our data are consistent with the previously reported behavioural face perception impairment. These findings suggest that although low- to mid-level spatial vision is intact, a lack of binocularity from early monocular enucleation specifically disrupts the behavioural and neural development of face perception, but not other forms of higher-level image category processing.