Accurate rapid averaging of multihue ensembles is due to a limited capacity subsampling mechanism

It is claimed that the extraction of average features from rapidly presented ensembles is holistic, with attention distributed across the whole set. We investigated whether observers’ extraction of mean hue is holistic or could reflect subsampling. Analysis of selections for the mean hue revealed a distribution that peaked at the expected mean hue. However, an ideal observer simulation suggested that a subsampling mechanism incorporating just two items from each ensemble would suffice to reproduce the precision of most observers. The results imply that hue may not be averaged as holistically and efficiently as other attributes.