The Representation of Simple Ensemble Visual Features Outside the Focus of Attention

Abstract

The representation of visual information inside the focus of attention is precise relative to the representation of information outside the focus of attention. We find that the visual system can compensate for the cost of withdrawing attention by pooling noisy local features and computing summary statistics. The location of an individual object is a local feature, while the center of mass of several objects (centroid) is a summary feature representing the mean object location. Three Experiments showed that withdrawing attention degraded the representation of individual positions more than the representation of the centroid. It appears that information outside the focus of attention can be represented at an abstract level which lacks local detail, but nevertheless carries a precise statistical summary of the scene. The term “ensemble features” refers to a broad class of statistical summary features, which we propose collectively comprise the representation of information outside the focus of attention.