All parts of an item are not equal: Effects of phonological redundancy on immediate recall

The process of redintegration is thought to use top-down knowledge to repair partly damaged memory traces. We explored redintegration in the immediate recall of lists from a limited pool of partly phonologically redundant pseudowords. In Experiment 1, four kinds of stimuli were created by adding the syllable /ne/ to two-syllable pseudowords, either to the middle (/tepa/ vs. /tenepa/) or to the end (/tepane/), or adding a different syllable to each item (/tepalo/, /vuropi/). The repeated syllable was thought to be available for redintegration. Lists of two-syllable pseudowords were recalled best, items with a redundant end were intermediate, and items with a redundant middle-syllable were as hard as nonredundant three-syllable items. In Experiment 2, the last syllable was predictable from context but not shared between all stimuli, reducing phonological similarity between items. Performance did not differ from the situation with identicallast syllables. In Experiment 3, a shared first syllable had a detrimental effecton memory. An error analysis showed that beneficial redundancy effects were accompanied by harmful similarity effects, impairing memory for nonredundant syllables. The balance between the two effects depended on syllable position.     

Vocalization-at-presentation and immediate recall, with varying recall methods

In a free recall situation, written recall is superior to spoken recall, and evidence is adduced suggesting that this may be partly due to the fact that this method of recall permits greater freedom in ordering the material. Evidence is also adduced suggesting that voicing the material at presentation gives superior recall because of a facilitatory effect on storage. This interpretation is supported by the finding that the advantage of vocalizing is not affected by prior knowledge as to whether recall is to be oral or written, and by the suggestion that vocalized lists are more resistant to intra-trial interference than nonvocalized lists. In addition, two earlier observations were confirmed: first, that the advantage of voicing is most marked at fast rates of presentation; and secondly, voicing gives rise to a higher proportion of acoustic errors relative to the number of items incorrectly attempted.     

Rehearsal in immediate serial recall

We report for the first time overt rehearsal data in immediate serial recall (ISR) undertaken at three presentation rates (1, 2.5, and 5 sec/word). Two groups of participants saw lists of six words for ISR and were required either to engage in overt rehearsal or to remain silent after reading aloud the word list during its presentation. Typical ISR serial position effects were obtained for both groups, and recall increased with slower rates. When participants rehearsed, they tended to do so in a cumulative forward order up to Serial Position 4, after which the amount of rehearsal decreased substantially. There were similarities between rehearsal and recall data: Both broke down toward the end of longer sequences, and there were strong positive correlations between the maximum sequence of participants' rehearsals and their ISR performance. We interpret these data as suggesting that similar mechanisms underpin both rehearsal and recall in ISR.     

Proactive interference in immediate serial recall

Two experiments yielded significant inter-list proactive interference (PI) in immediate serial recall of nine-consonants lists. This argues against the assumption that intra-trial rehearsal is sufficiently powerful to prevent PI from occurring. In the first experiment PI proved to be more pronounced in the case of visually than of auditorily presented lists to the extent that the modality effect on the prerecent items could be completely attributed to PI. PI also enlarged the effect of output interference through reversed order recall. These findings were confirmed in the second experiment which also showed that the effect of PI persisted at a slower presentation rate, suggesting that the role of rehearsal in counteracting PI should not be overestimated. Implications of these results for current notions on short-term retention are discussed.     

Transposition asymmetry in immediate serial recall

When participants confuse the position of items in immediate serial recall, they tend to recall transposed items too early rather than too late. This asymmetry of transposition errors was observed in four experiments. It increased as a function of list length, but was independent of report order, output position, cueing condition, and recall mode. The transposition asymmetry is consistent with error patterns in free recall and in regular speech production where transpositions are usually forward-looking. The asymmetry of transposition errors is discussed in terms of models of serial memory.     

Transposition asymmetry in immediate serial recall

When participants confuse the position of items in immediate serial recall, they tend to recall transposed items too early rather than too late. This asymmetry of transposition errors was observed in four experiments. It increased as a function of list length, but was independent of report order, output position, cueing condition, and recall mode. The transposition asymmetry is consistent with error patterns in free recall and in regular speech production where transpositions are usually forward‐looking. The asymmetry of transposition errors is discussed in terms of models of serial memory.     

Output order in immediate serial recall

In two experiments, we examined the effect of output order in immediate serial recall (ISR). In Experiment 1, three groups of participants saw lists of eight words and wrote down the words in the rows corresponding to their serial positions in an eight-row response grid. One group was precued to respond in forward order, a second group was precued to respond in any order, and a third group was postcued for response order. There were significant effects of output order, but not of cue type. Relative to the forward output order, the free output order led to enhanced recency and diminished primacy, with superior performance for words output early in recall. These results were replicated in Experiment 2 using six-item lists, which further suggests that output order plays an important role in the primacy effect in ISR and that the recency items are most highly accessible at recall.     

Phonological information in immediate and delayed sentence recall

Potter and Lombardi (1990) state in their conceptual regeneration hypothesis that immediate sentence recall is only based on conceptual and lexical information; phonological information does not contribute. As experimental evidence for this hypothesis, they reported that if a sentence is followed by a word list that included a lure word similar to one of the content words of the sentence (target word), the lure word frequently intrudes into sentence recall. We demonstrated that Potter and Lombardi did not observe any influence of phonological information because list presentation followed sentence presentation, and phonological information was discarded. We observed that phonological information influenced the intrusion rate if recall was not delayed by the subsequent presentation of a word list. With immediate recall, the lure intrusion effect disappeared in auditorily presented sentences. This shows that, if available, phonological information contributes to sentence recall.     

Phonological and semantic strategies in immediate serial recall

It has been suggested that certain theoretically important anomalous results in the area of verbal short-term memory could be attributable to differences in strategy. However there are relatively few studies that investigate strategy directly. We describe four experiments, each involving the immediate serial recall of word sequences under baseline control conditions, or preceded by instruction to use a phonological or semantic strategy. Two experiments varied phonological similarity at a presentation rate of one item every 1 or 2 seconds. Both the control and the phonologically instructed group showed clear effects of similarity at both presentation rates, whereas these were largely absent under semantic encoding conditions. Two further experiments manipulated word length at the same two rates. The phonologically instructed groups showed clear effects at both rates, the control group showed a clear effect at the rapid rate which diminished with the slower presentation, while the semantically instructed group showed a relatively weak effect at the rate of one item per second, and a significant reverse effect with slower presentation. The latter finding is interpreted in terms of fortuitous differences in inter-item rated associability between the two otherwise matched word pools, reinforcing our conclusion that the semantically instructed group were indeed encoding semantically. Implications for controlling strategy by instruction are discussed.     

Music-dependent memory in immediate and delayed word recall

Undergraduate volunteers rated a series of words for pleasantness while hearing a particular background music. The subjects in Experiment 1 received, immediately or after a 48-h delay, an unexpected word-recall test in one of the following musical cue contexts: same cue (S), different cue (D), or no cue (N). For immediate recall, context dependency (S-D) was significant but same-cue facilitation (S-N) was not. No cue effects at all were found for delayed recall, and there was a significant interaction between cue and retention interval. A similar interaction was also found in Experiment 3, which was designed to rule out an alternative explanation with respect to distraction. When the different musical selection was changed specifically in either tempo or form (genre), only pieces having an altered tempo produced significantly lower immediate recall compared with the same pieces (Experiment 2). The results support a stimulus generalization view of music-dependent memory.     

Vocalization-at-presentation and immediate recall, with varying presentation-rates

An experiment is reported in which the subject read visually presented lists with four different degrees of vocalization; immediately after reading each list he was required to reproduce it either aloud or in writing. Each list consisted of eight consonants and presentation rates were varied between I and 4 letters per sec. For any given series of lists, the subject was asked either to read the letters silently, or to mouth them silently, or to whisper them, or to say them aloud while reading.

At the fastest presentation-rate immediate recall improved monotonically with the degree of vocalization during reading of the lists; at slower rates this generalization held less well, especially for the lower degrees of vocalization. Vocalization was most helpful at the highest presentation-rate.

The overall amount correctly recalled was better for more slowly presented lists and for written as opposed to spoken recall. Analysis of the errors suggested that acoustic confusions were affected by the conditions of presentation; and that serial order intrusions were independent of presentation-or recall-conditions. An apparent variation of transpositions with voicing-and-recall-method failed to reach statistical significance. Theoretical implications of the experiment are discussed, including reference to Broadbent's theory of short-term memory (1958).     

Phonological and semantic strategies in immediate serial recall

It has been suggested that certain theoretically important anomalous results in the area of verbal short-term memory could be attributable to differences in strategy. However there are relatively few studies that investigate strategy directly. We describe four experiments, each involving the immediate serial recall of word sequences under baseline control conditions, or preceded by instruction to use a phonological or semantic strategy. Two experiments varied phonological similarity at a presentation rate of one item every 1 or 2 seconds. Both the control and the phonologically instructed group showed clear effects of similarity at both presentation rates, whereas these were largely absent under semantic encoding conditions. Two further experiments manipulated word length at the same two rates. The phonologically instructed groups showed clear effects at both rates, the control group showed a clear effect at the rapid rate which diminished with the slower presentation, while the semantically instructed group showed a relatively weak effect at the rate of one item per second, and a significant reverse effect with slower presentation. The latter finding is interpreted in terms of fortuitous differences in inter-item rated associability between the two otherwise matched word pools, reinforcing our conclusion that the semantically instructed group were indeed encoding semantically. Implications for controlling strategy by instruction are discussed.     

Explanations of grouping in immediate ordered recall

This article is about grouping in immediate ordered recall. The following findings are reported: (1) grouping a presentation improves recall, even when steps are taken to prevent rehearsal; (2) grouping primarily improves recall of the items adjoining the grouping, creating primacy and recency within groups; and (3) this primacy and recency are found even when single, isolated errors in recall are considered. These results suggest that the effects of grouping cannot be fully explained by rehearsal, chunking, or the number of directions in which an item can be transposed. It is suggested instead that (1) the auditory short-term store contains an unparsed and uncategorized representation that must be parsed and categorized just prior to recall, in a process of recovery; (2) items adjoining the boundary of a presentation are more easily recovered; and (3) grouping creates a boundary within the presentation. To support this explanation, a final experiment demonstrates an interaction between type of stimuli and serial position, with grouping most improving recall of adjoining phonemes.     

Recency and the modality effect in immediate ordered recall

In immediate ordered recall, recency is the improved recall of the last item of a presentation, and the modality effect is the advantage for an acoustic presentation over a subvocalized visual presentation, primarily occurring at the last serial position. Experiment 1 tested grouped presentations. There was a modality effect for the first item of the last group, even though that item was at the third-to-last or fourth-to-last serial position. In Experiment 2, for vocalized presentations of syllables ending in a, recency was larger for staccato speech than legato speech; for subvocalized presentations, there was a substantial recency for the legato style. In Experiment 3, recency was larger for a set of syllables ending in ATE than for a set of syllables ending in AME. These results suggest that recency cannot be explained by the existence of a fixed-capacity store, auxiliary to the auditory short-term store, that retains only some types of presentations. It is suggested instead that recency might reflect an auxiliary method of using the information in the auditory short-term store.     

Input and output modality effects in immediate serial recall

In immediate recall tasks, visual recency is substantially enhanced when output interference is low (Cowan, Saults, Elliott, & Moreno, 2002 Cowan, N., Saults, J. S., Elliott, E. M. and Moreno, M. V. 2002. Deconfounding serial recall. Journal of Memory & Language, 46: 153–177. [Crossref], [Web of Science ®] , [Google Scholar]; Craik, 1969 Craik, F. I. M. 1969. Modality effects in short-term storage. Journal of Verbal Learning & Verbal Behavior, 8: 658–664. [Crossref] , [Google Scholar]) whereas auditory recency remains high even under conditions of high output interference. This auditory advantage has been interpreted in terms of auditory resistance to output interference (e.g., Neath & Surprenant, 2003 Neath, I. and Surprenant, A. M. 2003. Human memory: An introduction to research, data and theory, London: Thomson Learning.  [Google Scholar]). In this study the auditory-visual difference at low output interference re-emerged when ceiling effects were accounted for, but only with spoken output. With written responding the auditory advantage remained significantly larger with high than with low output interference. These new data suggest that both superior auditory encoding and modality-specific output interference contribute to the classic auditory-visual modality effect.     

Spatial clustering and hierarchical coding in immediate serial recall

Four experiments are reported that demonstrate the benefits of clustering by spatial proximity in spatial serial recall and provide support for the notion that hierarchical coding underpins the retention of clustered sequences in spatial working memory. Sequences segregated by spatial clusters increased serial recall performance at different levels of sequence length in a variation of the Corsi test and produced a faster initial response time (RT), which indicates that they afforded data reducing processes. RT at cluster boundary increased in parallel with the number of items forming the clusters, suggesting that subroutines of different length were responsible for the ordering of items within clusters of different size. Evidence for hierarchical coding was also obtained in a serial recognition task, indicating this type of representation pertains to the retention of the sequences rather than exclusively to the organisation of the motor plan for the reproduction of the sequences.