Four effects-the word length effect, the irrelevant speech effect, the acoustic confusion effect, and the concurrent articulation effect-have played a prominent role in the development of influential theories of immediate memory. Indeed, accounting for these four findings was one of the motivations for creating the phonological loop component of working memory (Baddeley, 1992), and these effects are seen as key data that computational models of short-term memory must account for (Lewandowsky & Farrell, 2008). Despite the numerous studies examining these phenomena, very few studies have examined them using backward recall. To that end, one purpose of the four experiments reported here was to assess whether the four benchmark effects of working memory are observable with backward recall. A second purpose was to test the predictions of two models of memory: Despite their many differences, both the primacy model (Page & Norris, 1998) and the feature model (Nairne, 1990) predict that all four effects should be observed with backward recall.
Empirical ReviewWord length effect. The word length effect refers to the finding that lists of short (i.e., one-syllable) words are recalled better than otherwise comparable lists of longer (i.e., multisyllabic) words (Baddeley, Thomson, & Buchan an, 1975; for a review, see . The standard paradigm is forward immediate serial recall, but the word length effect is also observable with reconstruction of order (Nairne, Neath, & Serra, 1997), serial recognition (Baddeley, Chincotta, Stafford, & Turk, 2002), free recall (Watkins, 1972), single-item probe recall (Avons, Wright, & Pammer, 1994), and complex span (Tehan, Hendry, & Kocinski, 2001) tests. However, only a small number of studies have examined whether the effect is observable with backward recall.Cowan et al. (1992, Experiment 3) had subjects recall lists of short and long words in both a forward and a backward order, and recall direction was not known until test. However, a straightforward interpretation of the results is difficult, since word length was manipulated within a list (i.e., the first half of the list was short words, the second half long words), and since the lists had five items, there were not equal numbers of short and long items per list. Moreover, the stimuli used have since been shown to be atypical (see, e.g., Neath, Bireta, & Surprenant, 2003). Cowan, Wood, and Borne (1994) Working memory was designed to explain four benchmark memory effects: the word length effect, the irrelevant speech effect, the acoustic confusion effect, and the concurrent articulation effect. However, almost all research thus far has used tests that emphasize forward recall. In four experiments, we examine whether each effect is observable when the items are recalled in reverse order. Subjects did not know which recall direction would be required until the time of test, ensuring that encoding processes would be identical for both recall directions. Contrary to predictions of both the primacy model and the feature model, the benchm...