Tailgate Masking

This is Arielle Veenemans' PhD study showing the suppression of a target that is in plain view. A set of 4 pink letters step though 10 positions around fixation — be sure to fixate the centre after starting the movie. Three of the targets have leading masks that step with them through the same positions. These targets are not seen even though they are right there in the empty spaces between the masks — you can look directly at them or stop the movie and inspect these locations to verify that the targets are there. This is masking of a target by the noise pattern that was previously at the target's location. It no longer overlaps it. So visibility is bad when a target follows a mask closely — tailgating. This indicates that the masking is what is called "interruption" masking, it blocks the stimulus from reaching higher levels of processing. One of the targets — the leading one — has only the trailing mask and is easily seen. The trailing mask adds noise to the signal but not enough to block the target's recognition.

Veenemans, A. & Cavanagh, P. (2015). An unattended mask makes an attended target disappear. Journal of Vision, 15(14): 1-13. PDF