| Popis: |
There appear to be three independent systems for allocating attention: space-based, feature based, and object-based. Here, we review the literature of object-based attention to determine its underlying mechanisms. First, findings from unconscious priming and cuing suggest that the pre-attentive targets of object-based attention can be fully developed object representations. Next, the control of object-based attention appears to come from ventral visual areas specialized in object analysis that project downward to early visual areas. Whether feedback from object areas can accurately target the object’s specific locations and features is controversial, but recent work in autoencoding has made this plausible. Finally, we suggest that the three classic modes of attention may not be as independent as is commonly considered, and instead could rely on object-based attention for all three modes of selection. Specifically, studies show that attention can spread over the separated members of a group – without affecting the space between them — matching the defining property of feature-based attention. At the same time, object-based attention directed to a single small item has the properties of space-based attention. Nevertheless, the evidence for a parallel, space-based selection controlled through saccade centers is also convincing. We outline the architecture for this combined system and discuss how it works in parallel with other attention pathways. |
