Abstract
We live in a cluttered, dynamic visual environment that poses a problem: to perceive objects, the visual system must integrate information over space and time. Does a single, omnibus mechanism carry out this grouping operation, or does grouping depend on separate mechanisms each specialized for different feature aspects of the object? To address this question, we used a Quest procedure to measure thresholds for detecting static fragmented figures in noise and dynamic point-light biological motion figures in noise, in a large group of young adults. As expected, there were substantial individual differences in performance on both tasks, but correlation between the measures was not significant. These results imply that these two tasks rely on different integrative mechanisms, and it is tempting to think about those mechanisms in terms of the dorsal and ventral stream pathways.