Detecting and remembering simultaneous pictures in a rapid serial visual presentation.

Viewers can easily spot a target picture in a rapid serial visual presentation (RSVP), but can they do so if more than 1 picture is presented simultaneously? Up to 4 pictures were presented on each RSVP frame, for 240 to 720 ms/frame. In a detection task, the target was verbally specified before each trial (e.g., man with violin); in a memory task, recognition was tested after each sequence. Target detection was much better than recognition memory, but in both tasks the more pictures on the frame, the lower the performance. When the presentation duration was set at 160 ms with a variable interframe interval such that the total times were the same as in the initial experiments, the results were similar. The results suggest that visual processing occurs in 2 stages: fast, global processing of all pictures in Stage 1 (usually sufficient for detection) and slower, serial processing in Stage 2 (usually necessary for subsequent memory).