Large-scale examination of the benefit and cost of spatial attention and their variability

Spatial attention—the ability to prioritize relevant regions in our environment—is crucial for human cognition and has accordingly been studied extensively. However, large population samples have seldom been used, leaving inter-individual variability largely unexamined. Moreover, the relatively scarce studies that did consider individual differences in spatial attention did not include a baseline condition in which neutral cues do not guide attention to a particular location. This is important because a neutral condition is necessary for the distinction between attentional benefit (improved performance when attending the correct location) and attentional cost (impaired performance when attending the wrong location), and this distinction is critical for differentiating facilitatory from inhibitory mechanisms. Here, we recruited a sizable participant pool (N=438) across three experiments. The task was an acuity task with a Landolt square target that could appear in one of four possible locations. We included valid, invalid, and neutral conditions, in which precues indicated the right, wrong, or no location, respectively. We also performed a direct comparison of two types of neutral cues (a central neutral cue—a small bar presented at the center of the screen and a multi-cue with which four small bars cued all possible locations simultaneously). We measured both accuracy and RT and analyzed both the averaged attentional benefits and costs as well as their inter-individual variability. We found robust attentional benefits with high levels of inter-individual variability. In contrast, the cost averages and inter-individual distributions depended on the performance measurement (accuracy vs. RT), the cue-target distance, and the type of neutral cue. These findings provide a more refined understanding of the attentional mechanisms. Additionally, the direct comparison of the different types of neutral cue marked the ‘multi-cue’ as an optimal baseline for assessing both facilitatory and inhibitory aspects of spatial attention.