Abstract
Patients with visual agnosia can show improved recognition for real-world objects – a phenomenon known as the 'Real Object Advantage'. Although some have argued that this phenomenon is attributable to additional stereo cues present in real objects (but not planar images), an intrinsic feature of most real objects is that retinal size corresponds to the object's physical size. Conversely, the size of an object as represented in a two-dimensional image does not convey definite physical size cues. Here we investigated whether expectations about real world size influence object recognition. We studied recognition performance in a patient with bilateral LOC lesions and profound visual form agnosia, and a group of neurologically healthy observers. The stimuli were 3D-printed common objects, whose physical size either corresponded with real world size, or was scaled 50% smaller, or 50% larger, than the object's normal size. Recognition performance was contrasted for the real objects versus images of the same items matched closely for size, viewpoint, and illumination. In both the patient, and healthy observers, recognition was superior for normally-sized real objects, versus the scaled objects. Conversely, for images displays, the size manipulation did not influence recognition performance. Our data demonstrate that the 'Real Object Advantage' is a recognition phenomenon not limited to cases of visual agnosia, and that physical size is an integral component of normal mental object representations.
Meeting abstract presented at VSS 2016