Davies, S. 1 , Walker, P. 2 & Ziessler, M. 1
1 Psychology Department, Liverpool Hope University, Liverpool, UK.
2 Department of Psychology, Lancaster University, Lancaster, UK.
Previous research suggests that binding between features from different dimensions supports the view that representations in visual short-term memory (VSTM) can be object-based. An alternative account to object-based storage is independent feature-based modules. To test for this previous research used bi-coloured objects in a VSTM task and observed object-based binding. These results have not successfully been replicated. To further explore the possibility of object-based within-dimension feature binding in VSTM, two change detection experiments are reported. These involved memory for either two pairs of coloured squares abutting one another (forming single bi-coloured objects) or two pairs of coloured squares separated by a small gap. Using these stimuli the first experiment saw no object-based benefit for bi-coloured objects. The second experiment used the same stimuli with the exception that all displays were partially covered by an occluding surface with holes through which surface colours could be seen. Same-object benefits were observed when perceptual completion was possible, demonstrating object-based feature binding for features from the same dimension. The role of perceptual completion as an object-based mechanism is discussed, as is the nature of object-based representations in VSTM.