Cross-Modal Priming and Explicit Memory in Patients with Verbal Production Deficits

Abstract

Implicit memory is often thought to reflect an influence of past experience on perceptual processes, yet priming effects are found when the perceptual format of stimuli changes between study and test episodes. Such cross-modal priming effects have been hypothesized to depend upon stimulus recoding processes whereby a stimulus presented in one modality is converted to other perceptual formats. The present research examined recoding accounts of cross-modal priming by testing patients with verbal production deficits that presumably impair the conversion of visual words into auditory/phonological forms. The patients showed normal priming in a visual stem completion task following visual study (Experiment 1), but showed impairments following auditory study in both implicit (Experiment 2) and explicit (Experiment 3) stem completion. The results are consistent with the hypothesis that verbal production processes contribute to the recoding of visual stimuli and support cross-modal priming. The results also indicate that shared processes contribute to both explicit memory and cross-modal implicit memory. © 1999 Academic Press Implicit memory occurs when behavior is affected by previous experience without intentional, conscious recollection of that experience (Roediger & McDermott, 1993;Schacter, 1987). Perceptual or data-driven implicit memory tasks are those in which memory is cued by a stimulus that is physically related to the target stimulus. For example, in word-stem completion, participants might study the word TRUCK then their memory would be cued indirectly by asking them to complete three-letter stems including TRU . Per-

Auditory Priming within and across Modalities: Evidence from Positron Emission Tomography

“…Although we must be cautious when interpreting these trends, they ªt well with previous cognitive studies that have highlighted differences between within-and cross-modality priming. One class of explanations has focused on the idea that cross-modal priming is mediated by some form of abstract lexical representation involved in phonological input or output processing (e.g., Curran et al, 1999;Kirsner et al, 1989;Weldon, 1991). Previous neuroimaging studies have suggested that regions of the left posterior parietal cortex (BA 39/40), in the vicinity of the region that showed a decrease during cross-modal priming, are involved in phonological storage processes (Awh et al, 1996;Paulesu, Frith, & Frackowiak, 1993).…”

“…However, previous evidence from both cognitive studies (e.g., Kirsner, Dunn, & Standen, 1989;Jacoby et al, 1993;Richardson-Klavehn & Gardiner, 1996) and neuropsychological investigations (e.g., Curran, Schacter, & Galluccio, 1999) suggests that different mechanisms underlie within-and cross-modality priming on the stem completion task. More speciªcally, it has been suggested that cross-modality priming is mediated by (1) some form of abstract lexical representation involved in phonological input or output processing (e.g., Curran et al, 1999;Kirsner et al, 1989;Weldon, 1991) and (2) aspects of explicit retrieval (Jacoby et al, 1993;Richardson-Klavehn & Gardiner, 1996). Although these issues have not been examined previously in neuroimaging studies, we were particularly interested in the possibility that regions previously implicated in phonological processing and explicit retrieval would be associated with cross-modality priming.…”

Equivalent inter- and intramodality long-term priming: Evidence for a common lexicon for words seen and words heard

“…The issue of pure versus mixed study lists-the contrast of between-subjects and within-subjects designs-is certainly central to the contradiction. Curran, Schacter, and Galluccio (1999) admitted being puzzled by the finding that, for their normal participants, the intermodal priming that they investigated in their Experiment 2 was as substantial as the intramodal priming that they investigated in their Experiment 1. Curran et al confronted the issue of the sensitivity of implicit memory to modality change outside the within-subjects design and failed to observe the expected inferiority of cross-modality priming.…”

Visual–Auditory Events: Cross-Modal Perceptual Priming and Recognition Memory

“…Furthermore, specific and nonspecific components are not additive (Schacter & Graf, 1989, experiment 4), suggesting some mechanism of perceptual sharing (cf., Gibson, 1966) may account for crossmodal priming. Several studies show that visual-auditory cross-modal priming for words may be mediated presemantically by phonological or lexical codes (Curran, Schacter, & Galluccio, 1999;Komatsu & Naito, 1992;Postman & Rosenzweig, 1956). These studies converge on the notion that cross-modal priming results from perceptual representations which are not limited to modality-specific processes and systems.…”