Figure 1.

Examples of RDKs used in the temporal and spatiotemporal experiments. In each experiment, observers judged whether sequentially presented standard or comparison RDKs had a more clockwise direction of motion. Temporal and spatial dot directions were sampled with replacement from an asymmetrical probability distribution with distinct measures of central tendency. All dots in the temporal comparison were displaced in the same randomly sampled direction on each image, generating a temporal sequence of directions across images; individual dots in the spatial comparison were displaced in independently sampled directions on each image, generating a spatial distribution of directions on each image. The comparison RDKs used for the spatiotemporal experiments consisted of different mixtures of spatial and temporal dot directions.