A Phonological Account for the Cross-Language Variation in Working Memory Processing
Cheung, Him, Kemper, Susan, Leung, E., The Psychological Record
This study examines the relationship between immediate serial recall and word articulation rate with Cantonese and English materials. Using bilingual subjects, Experiment 1 reported a steeper regression function relating recall to word articulation rate for Cantonese than for English items. The effect of language on regression slopes was shown to hold both with and without concurrent articulation (i.e., subjects repeating irrelevant digits during list learning and recall, thus blocking any articulatory mechanisms), although it was significantly more pronounced in the latter condition. In Experiment 2, the effect of language on slopes was replicated in monolingual English speakers, using pseudowords that preserved the consonant-vowel structures of the Experiment 1 items. These findings indicate that (1) both articulatory and nonarticulatory processes contribute to the cross-language variation in regression slopes and (2) the language effect is attributable to a difference in consonant-vowel structures of the items from the two languages. It is concluded that the phonological loop model (Baddeley, 1986), which specifies an articulatory rehearsal process and a nonarticulatory phonological store, is applicable to cross-language working memory processing.
The positive relationship between short-term recall and word articulation rate has been established as a general phenomenon for English words of various lengths (Baddeley, Thomson, & Buchanan, 1975; Cowan, 1992; Cowan, Day, Saults, Keller, Johnson, & Flores, 1992; Hulme, Maughan, & Brown, 1991; Schweickert & Boruff, 1986; Standing, Bond, Smith, & Isely, 1980). Generally speaking, words that could be uttered fast tend to be recalled better. Emphasizing the predictive role of word articulation rate, some previous authors have used it to explain important variations in short-term recall. For instance, Hulme, Thomson, Muir, and Lawrence (1984) demonstrated that the developmental increase in short-term span from 4 years of age to adulthood could be completely explained by a corresponding increase in word articulation rate. A similar conclusion was reached by Nicolson (1981). Kynette, Kemper, Norman, and Cheung (1990) suggested that the reduced short-term span among older adults could as well be explained by a dec line in word articulation rate.
In a similar vein, word articulation rate might also account for cross-language variations in short-term recall. Ellis and Hennelly (1980) found that English-Welsh bilinguals had larger English digit spans than Welsh digit spans, and this was accompanied by a proportionally faster digit pronunciation rate in English than in Welsh. Hoosain and Salili (1987) and Hoosain (1979, 1982) had Cantonese-English bilinguals recall and articulate both Cantonese and English digits. Digit span was significantly greater in Cantonese than in English, and Cantonese digits were articulated more rapidly than English digits. Similar results were obtained by Stigler, Lee, and Stevenson (1986), who demonstrated that Chinese-speaking children had larger digit spans than their age-matched English-speaking counterparts; Chinese digits were also shown to be articulated more rapidly than English digits.
This consistent recall-articulation rate relationship is generally attributed to the articulatory rehearsal component of working memory (Baddeley et al., 1975), which operates like an audio tape running at a constant speed. A fast articulation rate enables a large amount of information being "recorded" onto this tape within a fixed period of time. Recall is thus enhanced. According to this view, the articulation rates of memory items constitute the dominant factor for recall; a constant recall-articulation rate function across different situations is thus expected. In other words, given the same rate of articulation and therefore the same rehearsal efficiency, very similar recall would result, regardless of the type of material, age of subjects, and so forth. …