Figure 2. Effect of availability of spatial attention on the outcome of FAS.

A) Experimental procedure (see Methods for details). A set of four letters was presented around the time of FAS, “bracketing” it by ±100 ms and was followed shortly by a mask. The response was collected after the stimulus presentation. B) Performance for the letter task in a single task (observers responded on letter task only) and dual task conditions. C) For all observers (near) absence of attention resulted in a highly significant drop of illusory motion reversal reports.