Abstract
It is considered that resolving global form involves processes taking place in the ventral visual pathway whereas resolving global motion involves processes taking place in the dorsal visual pathway. It remains unclear whether the two pathways interact or are independent of one another. We determined whether our ability to discriminate motion direction on a global motion coherence task was affected by the amount of global orientation coherence, and vice versa. The experiment was designed such as the same visual stimuli contained both orientation and motion information. It consisted in a set of 100 oriented gabors randomly placed within the 8 degrees of eccentricity that independently moved at 2 deg/s. Signal Gabors had either horizontal or vertical orientation and left/right motion direction, whereas noise Gabors had random orientation and random direction of motion. Subjects were informed of which information to respond to (orientation or motion) by a visual cue that was shown either before or after the presentation of the stimulus. The results based on 3 subjects showed that orientation information did affect performance on global motion and motion information did affect performance on global orientation, arguing in favor of two independent processes. Presenting the task cue before or after the visual stimulus did not change the performances.
Meeting abstract presented at VSS 2016