Localization of element clusters: multiple cues.

The visual system commonly has to estimate the relative location of a textured region but the stimulus features used to perform that task are yet to be determined. The use of centroid, midpoint and peak activity cues would all be reasonable. In the current experiment an attempt was made to assess the relative efficacy of these three cues. The observers were required to indicate whether a cloud of either 3, 10 or 100 elements was located to the left or right of an imaginary line formed between two reference elements. Performance was compared to that expected from the use of the three cues. It was concluded that the cue used varied as the characteristics of the cloud changed and therefore that the visual system is not restricted to the use of a single cue type when localizing object clusters.