Task-irrelevant inputs alter ensemble representations of faces within the spatial focus of attention

Spatial attention enhances processing of information, but how does unattended and task-irrelevant information influence visual processing within the spatial focus of attention? We tested this by asking participants to extract the average emotional expression of a set of sequentially presented faces while simultaneously presenting task-irrelevant faces at a spatially unattended and task-irrelevant location. Across several experiments, we found that participants' reports of the emotional expression of faces at the attended location were biased toward the task-irrelevant faces. For example, when happier faces were presented at the unattended location, participants were biased to perceive the attended faces as happier. A control experiment in which participants were asked to also detect probes at cued and uncued locations showed that spatial attention was directed towards the cued location as instructed. Together, these results reveal that unattended and task-irrelevant inputs do not only affect the efficiency of target processing, for example by slowing responses or lowering accuracies, but that they can systematically bias ensemble representations within the spatial focus of attention. (PsycInfo Database Record (c) 2024 APA, all rights reserved).