Abstract
Peripheral vision has been found to be preferentially attuned to motion information. To examine whether this advantage extends to shape identification, we had subjects match pairs of Attneave-style polygons presented 10° from fixation under three form-definition conditions: Static, Form-from-motion, Form translation. In all cases, the interior and exterior of the shapes were filled with luminance noise having a Gaussian distribution. In the static condition, the interior of the shapes was made darker than the surround, providing a luminance cue to form. In the form-from-motion condition, the interior and exterior of the shapes scrolled in opposite directions. In the translation condition, the entire shape moved up and down against the background. Pairs of shapes were presented to one side of fixation, either left or right. The subjects' task was to say whether the two shapes matched or not. Different levels of difficulty were achieved by having the shapes vary in complexity. Stimulus pairs were presented for 250 ms and fixation was monitored with an Eyelink II eye-tracker to ensure that the stimuli were presented in the periphery. Our findings showed that translation provided a significant advantage over the other two conditions in terms of accuracy. This result suggests that the advantage for motion detection in the peripheral system extends to the identification of complex shapes, but only when the motion is of the first and not the second-order.