Abstract
The face inversion effect (FIE) is often attributed to the inability of the human face recognition system to simultaneously perceive multiple features of an inverted face and integrate them into a single global representation, a process called holistic processing. If inversion reduces holistic processing, then for inverted faces the functional visual field should be constricted, as opposed to global (expanded) for upright faces. Until now, however, there are only indirect indications supporting this hypothesis. In the current experiment, we directly manipulated holistic processing by using a gaze-contingent technique allowing manipulation of the amount of facial features simultaneously perceived. First, a gaze-contingent foveal mask covering all foveal information prevented the use of high resolution information, necessary for part-based processing, but allowed holistic processing based on lower resolution peripheral information. Second, a gaze-contingent foveal window covering all peripheral information prevented the simultaneous use of several facial features, but allowed detailed investigation of each feature individually. A delayed face matching task showed an increased FIE with a foveal mask compared to full view and an almost absent FIE with a foveal window. These data provide direct evidence that the FIE is caused by the inability to process inverted faces holistically.