Using a picture naming task, we compared the magnitude of repetition p
riming after one prior study episode (single test priming) versus mult
iple prior study presentations (multiple test priming). Pictures were
repeated either one, two, or three times, and the interval between tes
ts was either several minutes (blocked test) or one week (spaced test)
. Priming increased with additional prior presentations (beyond one) i
n the multiple test format. In addition, single test priming decreased
within one hour after initial. exposure, with little change from one
hour to two weeks. Priming was unaffected by a simultaneous recognitio
n task, suggesting that picture naming is an implicit task relatively
immune from explicit memory contamination.