Abstract
When a large frame is presented offset from an observer's objective midline, the observer's egocentric reference frame becomes distorted, with the perceived midline biased in the direction of the frame's offset (Dassonville & Bala, 2004). This distortion, in turn, causes mislocalizations of both the frame (the Roelofs effect, Roelofs, 1936) and visual probes located within the frame (the induced Roelofs effect, Bridgeman et al., 1997a). A search for an auditory analogue of the Roelofs effect indicated that auditory contextual information is capable of causing a mislocalization of auditory probes (Bridgeman et al., 1997b), but these results have been interpreted as being contrast effects occurring in an allocentric reference frame, rather than being caused by a distortion of the egocentric reference frame (Getzmann, 2003). If an auditory Roelofs effect does not in fact exist, it is unclear whether this is because auditory contextual information is incapable of causing a distortion of the egocentric reference frame, or because auditory probes are localized within a reference frame that is immune to the effects of Roelofs-inducing contextual information, whether visual or auditory in nature. To address this ambiguity, we employed a crossmodal Roelofs design in two experiments: 1) localization of auditory probes in the presence of an offset visual frame; and 2) localization of visual probes in the presence of an offset auditory scene. Auditory and visual probes were found to be equally susceptible to the induced Roelofs effect caused by a visual frame, supporting models of a shared egocentric reference frame for encoding the location of stimuli in both sensory domains. In contrast, the lateral offset of an auditory scene had no effect on visual localization, indicating that auditory context, unlike visual context, does not contribute to the establishment of the egocentric reference frame.
Meeting abstract presented at VSS 2016