AMERICAN JOURNAL OF PSYCHOLOGY Fall 2000, Vol. 113, No.3, pp.341-358 The Role of Selective Attention in Perceptual and Affective Priming MARIA STONE NASA-Ames Research Center Stanford University SANDRA L. LADD West Valley College JOHN D. E. GABRIELI Stanford University Two kinds of perceptual priming (word identification and word fragment completion), as well as preference priming (that may rely on special affective mechanisms) were examined after participants either read or named the colors of words and nonwords at study. Participants named the colors of words more slowly than the colors of nonwords, indicating that lexical processing of the words occurred at study. Nonetheless, priming on all three tests was lower after color naming than after reading, despite evidence of lexical processing during color naming shown by slower responses to words than to nonwords. These results indicate that selective attention to (rather than the mere processing of) letter string identity at study is important for subsequent repetition priming. Priming and divided attention Repetition priming tasks measure memory as the change in speed, accuracy, or bias in responses to studied relative to baseline items. Repetition priming often is intact in amnesic patients who cannot recollect study episodes (Cermak, Talbot, Chandler, & Wolbarst, 1985; Graf, Shimamura, & Squire, 1985; Graf, Squire, & Mandler, 1984; Shimamura, 1986; Vaidya, Gabrieli, Keane, & Monti, 1995; Verfaellie, Cermak, Letournean, & Zuffante, 1991) and is often independent of recall and recognition (explicit forms of memory) in normal participants (Jacoby & Dallas, 1981; Tulving, Schacter, & Stark, 1982). Thus, repetition priming need not depend on conscious or intentional recollection of study phase episodes at test time. These findings have led some researchers to propose that repetition priming depends on automatic, unintentional processing and thus should not be susceptible to the division of attention at study (Koriat & Feuerstein, 1976; Parkin, Reid, & Russo, 1990; Parkin & Russo, 1990; Szymanski & MacLeod, 1996). Despite this straightforward proposition, experimental evidence about the role of attention in repetition priming is mixed. Division of attention at study reduces priming in some cases (Eich, 1984; Gabrieli et al., 1998; Mulligan & Hartman, 1996) but not in other cases (Koriat & Feuerstein, 1976; Parkin et al., 1990; Parkin & Russo, 1990). Mulligan (Mulligan & Hartman, 1996; Mulligan, 1998) used the distinction between conceptual and perceptual tests of memory (Roediger & McDermott, 1996; Roediger, Weldon, & Challis, 1989) to explain inconsistencies in the literature. The distinction between conceptual and