The purpose of the present study was to investigate the effects of sel
ective attention and levels of processing (LOPs) at study on long-term
repetition priming vis-a-vis their effects on explicit recognition. I
n a series of three experiments we found parallel effects of LOP and a
ttention on long-term repetition priming and recognition performance w
hen the manipulation of these factors at encoding was blocked. When a
mixed study condition was used, both factors affected explicit recogni
tion, while their effect on repetition priming was determined by the n
ature of the test. Shallow processing at test did not benefit from lon
g-term repetition, regardless of whether the words had been studied de
eply or shallowly. Selective attention affected longterm repetition gr
iming in a semantic: but not in a lexical decision (LD), test. Regardl
ess of study condition, retention lag affected long-term repetition pr
iming only in the semantic test. These results suggest that if the exp
erimental conditions allow scrupulous selection of attended and unatte
nded information or narrow tuning to a shallow, pre-lexical LOP, impli
cit access to unattended or shallowly studied items is significantly r
educed, as is explicit recognition. We suggest a conceptual framework
for understanding the effects of LOP, attention, and retention interva
l on performance of explicit and implicit tests of memory. (C) 1998 El
sevier Science B.V. All rights reserved.