Episodic Memory Reflected in Printed Word Naming

Article excerpt

Although memory is typically measured by recall or recognition, it is also expressed by fluent or stylized task performance. In this experiment, 12 volunteers (called speakers) completed four experimental stages over a 2-week period. They read printed words aloud in two sessions, before and after exposure to auditory training tokens. They later completed a recognition memory test, discriminating old from new words. Groups of perceptual judges assessed the speakers' vocal imitation by comparing utterances recorded before and after training and deciding which sounded like "better imitations" of the training tokens. The data showed clear evidence of postexposure imitation, with systematic effects that preclude strategic explanations. The contents of episodic memory were reflected by participants' speaking style while they were reading aloud. Together, the imitation and recognition data suggest that memory preserves detailed traces of spoken words; those traces were apparently activated when participants later read the same words in the same context.

In a classic article, Oldfield (1966) described the mental lexicon, a collection of words in long-term memory that has been a focus of extensive investigation and theorizing. Within that enterprise, questions have arisen regarding the nature of lexical representation, and about the relationship of word recognition to either episodic or semantic memory. Generally there are two main views on lexical representation: Abstractionist theories view the lexicon as a set of ideal units (e.g., Bowers & Michita, 1998; Caramazza, Laudanna, & Romani, 1988; Humphreys, Evett, & Quinlan, 1990; Marslen-Wilson & Warren, 1994; Morton, 1979), whereas episodic theories assume that groups of detailed memory traces collectively represent individual words (Goldinger, 1998; Jacoby, 1983; see Bowers, 2000, and Tenpenny, 1995, for reviews). Naturally, given such poles, there are intermediate views, including those that inform mixed and distributed models (Brown & Carr, 1993; Stark & McClelland, 2000).

In some regards, theorizing about lexical representations appears rather schizophrenic, owing to the near-universal application of words as experimental stimuli. In psycholinguistics, words are fairly magical entities, representing the psychological level at which 26 meaningless letters coalesce into thousands of meaningful units. Many researchers study word recognition itself; others follow linguistic pathways higher, studying how words are integrated into discourse. In either circumstance, words are typically treated in a manner consistent with linguistic theory (Halle, 1985), as abstract, canonical units. Word recognition is appreciated for its stability despite variations and is theoretically likened to finding entries in a computer (Forster, 1979) or activating nodes (or patterns) in networks (Plaut, McClelland, Seidenberg, & Patterson, 1996).

In studies of general cognition, words are not the investigative focus but are used as a methodological convenience. Words are familiar, they can be manipulated along various dimensions (perceptual and conceptual), they have "builtin" manipulations (e.g., frequency variations), and they are plentiful. Words, presented in list format, are commonly used in memory research. Perhaps owing to these different empirical orientations toward words, different theoretical views have evolved across fields of research. In psycholinguistics, the abstract view is prominent; perception entails information reduction, matching tokens to types. This view is reasonable, since people are remarkably robust across perceptual variations in spoken- and printed-word perception. Moreover, word perception is rarely an end in itself, because people typically integrate words into discourse. Given these facts, it seems evident that some form of abstraction takes place in the mental lexicon (Bowers, 2000) or in memory at large.

Nevertheless, memory researchers have advanced theories with more dynamic portrayals of memory traces, including lexical representations. …