Masked pictures of objects were flashed so briefly that only 13.5% of them
could be named. Forced-choice accuracy for the unidentified objects was at
chance. When the pictures were shown again, about 15 min and 20 intervening
trials later without any indication of possible repetitions, naming accura
cy increased to 34.5%. The priming was completely visual, rather than seman
tic or verbal, as there was no priming of same-name, different-shape images
. This is the first demonstration of facilitatory visual recognition primin
g by unidentified pictures when the subject could not anticipate if when, o
r where the previously unidentified picture was to be shown again. A change
in the position of the object reduced but did not eliminate the priming, a
llowing a speculation that the locus of subliminal visual priming is at an
intermediate stage in the ventral cortical pathway for shape recognition.