Abstract
Previous studies of human memory have focused on stimuli in the form of two-dimensional images, rather than tangible real-world objects. Previously, we found a memory advantage for real-world objects versus colored photographs of the same items. A potential explanation for this 'real object advantage' (ROA) is that real objects (but not their representations) afford genuine physical interaction. Here, we examined directly whether the ROA is influenced by reachability by comparing memory performance for images versus real objects, when they are presented either within versus outside of reach. Participants were asked to memorize 112 different objects: half were real objects and the remainder were high-resolution color images of objects. Half of the stimuli in each display format were presented within reach, and the remainder were outside of reaching distance. The images were matched closely to the real objects for size, viewing angle, background and illumination. Participants completed a free recall task, a recognition task, and also a task in which they indicated whether the object was displayed as a real object or an image. We predicted that if graspability is important in driving the ROA, then stimuli positioned beyond reach should have no influence on memory for images, but should impair memory for real objects. In line with this prediction, we found that free recall for real objects was superior to images, but only when the objects were within reach. Conversely, recall for images was unaffected by distance, suggesting that the effect for the real objects was not attributable to distance-related changes such as retinal size. A similar pattern was observed in participants' ability to indicate the format in which the stimuli were presented Reachability is a critical determinant of the ROA.
Meeting abstract presented at VSS 2017