Brief video clips of random dot stimuli used in studies of extrastriate area MT. From the website: "Many of the perceptual tasks employed in the lab make use of a random dot stimulus. This stimulus consists of some small dots moving in a specified direction (signal dots) interspersed with others moving randomly (noise dots). By changing the ratio of signal to noise dots we can change the strength of the motion signal they carry. Perceptually, as the ratio of signal to noise dots (coherence) decreases, it becomes harder to tell in which direction the signal dots are moving. Below are a few Quicktime movies of random dot stimuli at different coherences. The quicktime player is needed to view these movies. Random Dots - 100% coherence, Random Dots - 30% coherence, Random Dots - 5% coherence, Random Dots - 0% coherence."