Abstract
Introduction. Previously, we have shown that people with one eye have enhanced sound localization (Hoover, Harris & Steeves, 2012, EBR) and lack the visual dominance commonly found in binocular and patched viewing controls (Moro & Steeves, 2011, EBR). These results persist despite evidence that their integration of the auditory and visual components of multisensory events, when determining spatial location, is optimal (Moro, Harris & Steeves, 2014, MSR). Currently, we conducted three behavioural studies to further explore audiovisual integration in people with one eye compared to binocular and patched viewing controls. Experiment 1. We investigated the temporal component of audiovisual integration, by measuring the temporal binding window (TBW). Participants performed an audiovisual simultaneity judgment task and people with one eye showed no difference in width of TBW compared to controls despite slower performance. Experiment 2. We measured the sound induced flash illusion (SF) where participants indicated the number of light flashes paired with multiple tones. People with one eye performed no differently from controls. Experiment 3. We measured the McGurk audiovisual illusion. People with one eye showed a reduced McGurk effect compared to controls. Conclusions. It is possible that these mixed findings reflect differences in levels of processing between the three tasks. Higher level audiovisual processing (McGurk) compared to lower level audiovisual processing (TBW and SF) might benefit more from potential changes in underlying neural connectivity with eye enucleation early in life. These findings provide further evidence for changes in sensory neural connectivity in people with one eye that may serve as cross-modal adaptation for the loss of binocularity during early brain development.
Meeting abstract presented at VSS 2015