Interactive visual and postvisual processes and their roles in form-specific memory.

Abstract Effects of depth of encoding on form-specific memory were examined. After viewing words (e.g., "bear") presented centrally during initial encoding, participants completed word stems (e.g., "BEA") presented laterally and pattern masked during subsequent test. When the encoding task was perceptual, letter-case specific memory was not observed, unlike in previous experiments without pattern masking. However, when the encoding task required both perceptual and conceptual processing, letter-case specific memory was observed in direct right-hemisphere, but not in direct left-hemisphere, test presentations, like in previous studies without pattern masking. Results were not influenced by whether stems were completed to form the first words that came to mind or words explicitly retrieved from encoding. Depth of encoding may influence form-specific memory through interactive processing of visual and postvisual information. An important aspect of repetition priming is that it can be form specific under some conditions. Form-specific word priming is measured as greater priming when words are presented in the same format (letter case and font) between the initial encoding of a word (e.g., "bear") and the subsequent test (e.g., "bear") compared with when words are presented in different formats between encoding (e.g., "BEAR") and test (e.g., "bear"). Letter-case specific priming is commonly observed (e.g., Jacoby & Hayman, 1987; Masson, 1986; Roediger & Blaxton, 1987). This effect is found when test items are presented directly to the right cerebral hemisphere, but not when they are presented directly to the left cerebral hemisphere (e.g., Marsolek, Kosslyn, & Squire, 1992; Marsolek, Schacter, & Nicholas, 1996; Marsolek, Squire, Kosslyn, & Lulenski, 1994; see also Marsolek, 1995, 1999, for similar results with objects and unfamiliar shapes), and it is found when serotonin levels in the brain are high, but not when serotonin levels are low (Burgund, Marsolek, & Luciana, 2003). However, many important questions remain unanswered regarding the experimental conditions that produce or enhance form-specific priming (e.g., see Bowers & Marsolek, 2003). Indeed, a curious aspect of the previous research is that seemingly contradictory results have been observed in studies of the effects of depth of encoding (Craik & Tulving, 1975) on visually specific priming (Graf & Ryan, 1990; Jacoby, Levy, & Steinbach, 1992). In this article, after considering these contradictory results, we test alternative theories of depth of encoding effects on form-specific memory. In doing so, we address important questions about the degree of interactivity between visual and postvisual processes. Research on depth of encoding and form-specific memory has produced contradictory results. Graf and Ryan (1990) observed greater form-specific word priming when participants performed a relatively shallow encoding task (rating the readability of the prime words) than when they performed a relatively deep encoding task (rating the likeability of the prime words). In contrast, Jacoby et al. (1992) observed greater form-specific word priming when encoding and test involved the relatively deep task of reading and answering short questions than when they involved the relatively shallow task of only reading the questions aloud. (Similarly, Woltz, 1990, also found form-specific priming when the encoding and test tasks involved semantic relatedness judgments for pairs of words, although no comparison was made between priming in this relatively deep task versus a relatively shallow task.) Why are such seemingly discrepant results obtained? These previous studies differed in many ways, but the following analysis highlights important variables that have been implicated by previous research. Potential answers for why seemingly discrepant results have been obtained arise from considerations of the functional and neural processes that may be involved in such memory effects. …