The benefits of getting horizontal

The goal of much research in vision is to better understand the mechanisms of attention. This is often accomplished by using models of attention to predict how the placement of stimuli on a computer screen will affect task difficulty. However, recent research has shown there are asymmetries in visual sensitivity across different locations of the visual field and also that there might be interactions between attention and sensitivity across different locations in the visual field. We discuss the potential significance of these asymmetries for attention research, focusing on the possibility of an attentional advantage for targets appearing horizontal to an invalid exogenous cue. We review previous literature concerning this potential horizontal advantage and then describe seven experiments related to it. Experiments 1 and 2 find an advantage for targets appearing horizontal, rather than diagonal, to an invalid cue in a visual display similar to those used in the classic Posner cueing paradigm. Experiments 3 and 4 provide evidence of an advantage for horizontal targets in a display similar to those used in the object-based attention literature. Experiment 5 attempted to determine whether flanking non-targets are necessary to observe a horizontal advantage, but ended up not providing much information. Experiments 6 and 7 attempted to test between two models of the horizontal advantage and, while perhaps ruling one out, do not provide clean evidence for any. In the end, we conclude that the evidence for the horizontal advantage is strong, though there is still much to learn about