How is location defined? Implications for learning and transfer of location-specific control.

Much research has explored location-specific proportion compatibility (LSPC) effects (i.e., how the appearance of a stimulus in certain locations can reactively trigger different attentional control settings) to elucidate mechanisms underlying reactive control. Recently, however, failures to reproduce key evidence showing transfer of LSPC effects (originally reported in Crump & Milliken, 2009) have called into question whether control per se supports these effects. Notably, Crump and Milliken (2009), and all studies attempting to reproduce their findings, presented stimuli in two locations, one above and one below fixation. Inspired by research on differences between horizontal and vertical meridians, we examined the consequences of defining location in this way compared with alternatives. Experiments 1 and 2 demonstrated that LSPC effects are robust when location is defined as left versus right and larger than when location is defined as upper versus lower, and additionally demonstrated LSPC effects for two locations within the same coarse spatial category (e.g., left vs. farther left). In Experiment 3, we aimed to reproduce Crump and Milliken's key findings using left and right locations for the first time. Critically, we found transfer of the LSPC effect to diagnostic items across two designs and the first evidence for a robust experiment wide LSPC effect for inducer items. Our findings support theories positing that LSPC effects reflect location-specific attentional and more generally suggest that choosing a definition of location is not a minor methodological decision but critically impacts learning and transfer of location-specific attentional control. (PsycInfo Database Record (c) 2022 APA, all rights reserved).