Capturing the suffix: Cognitive streaming in immediate serial recall.

Abstract

Adding an irrelevant item to the end of an auditory to-be-remembered list increases error on the last list items appreciably, known as the suffix effect. The phenomenon of auditory capture (e.g., Bregman & Rudnicky, 1975), namely, the tendency for a sequence of similar items to form a stream that at the same time isolates perceptually dissimilar members of the sequence, is exploited to explore the suffix effect. Irrelevant items interleaved between to-be-remembered items are used to capture the suffix with the aim of reducing its impact. Four experiments illustrate how the properties of the irrelevant sequence promote capture. The results are problematic for models of the suffix that involve masking of the last list item; instead, models based on grouping are favored.

Exploring the suffix effect in serial visuospatial short-term memory

“…This follows the precedent of Nicholls and Jones (2002), who pointed out that previous studies have varied in how recency was measured and that comparisons across investigations can therefore be difficult. The three measures of recency were (1) an absolute recency measure, comparing absolute accuracy performance in the suffix and control conditions at the last serial position; (2) a relative recency measure, comparing the relative increase in accuracy performance from the penultimate serial position to the last for the suffix and control conditions; and (3) a normalized recency measure, calculated as the proportion of accuracy performance at the last serial position on the sum of accuracy performance across all serial positions, again for the suffix and control conditions.…”

“…Although the mere presentation of a suffix may distract participants or capture their spatial attention (any suffix, even a tone, has a spatial locus), at least part of the suffix effect that we have reported seems to be related to the visuospatial nature of the suffix and the memory task. These results present implications both for the understanding of visuospatial serial memory and the study of the suffix effect, and further research is needed in order to explore factors modulating the suffix effect in visuospatial serial memory and to compare its underlying determinants with those observed in other domains (verbal, e.g., Nicholls & Jones, 2002;tactile, e.g., Mahrer & Miles, 1999;olfactory, e.g., Miles & Jenkins, 2000). The results still leave open the question of whether different memory systems are required for spatial material and for verbal material; the evidence presented here suggests that there are many common factors and that the differences can be explained by the functional peculiarities of the perceptual processing of stimuli rather than by mnemonic systems per se.…”

“…As has recently been pointed out by Nicholls and Jones (2002), the verbal literature on the suffix effect presents two major theoretical perspectives: the masking account and the grouping account. According to the masking account, serial recall performance for the last item of a TBR sequence is overwritten by the presentation of the suffix (e.g., Nairne, 1990).…”

“…According to the masking account, serial recall performance for the last item of a TBR sequence is overwritten by the presentation of the suffix (e.g., Nairne, 1990). From the grouping point of view, the suffix becomes part of the same cohort as the TBR items; that is, it is grouped with the TBR items (Frankish, 1989;Nicholls & Jones, 2002). The data of Nicholls and Jones clearly favor the grouping account, because they demonstrate that the suffix effect can be moderated by the extent to which the suffix can be segregated from the to-be-remembered items on the basis of auditory streaming (Bregman, 1990).…”

“…Since the earliest demonstrations of the suffix effect, it has been widely investigated (e.g., Baddeley & Hull, 1979;Balota & Engle, 1981;Beaman & Morton, 2000;Crowder & Morton, 1969;Greene, 1992;Greene & Crowder, 1988;Nicholls & Jones, 2002;Penney, 1985). Contemporary studies have shown that not only is marked recency not confined to the auditory verbal domain, it is also observed with visuoverbal material such as lipread lists (Campbell & Dodd, 1982;Divin, Coyle, & James, 2001;Gathercole, 1987) and, significantly, with visual nonverbal material, such as the position of objects in twodimensional space (e.g., Avons, 1998;Jones, Farrand, Stuart, & Morris, 1995), or even with auditory spatial stimuli (Parmentier & Jones, 2000).…”