Semantic Contribution to Immediate Serial Recall Using an Unlimited Set of Items: Evidence for a Multi-level Capacity View of Short-term Memory

Does learning to read shape verbal working memory?

Many experimental studies have investigated the relationship between the acquisition of reading and working memory in a unidirectional way, attempting to determine to what extent individual differences in working memory can predict reading achievement. In contrast, very little attention has been dedicated to the converse possibility that learning to read shapes the development of verbal memory processes. In this paper, we present available evidence that advocates a more prominent role for reading acquisition on verbal working memory and then discuss the potential mechanisms of such literacy effects. First, the early decoding activities might bolster the development of subvocal rehearsal, which, in turn, would enhance serial order performance in immediate memory tasks. In addition, learning to read and write in an alphabetical system allows the emergence of phonemic awareness and finely tuned phonological representations, as well as of orthographic representations. This could improve the quality, strength, and precision of lexical representations, and hence offer better support for the temporary encoding of memory items and/or for their retrieval.

Grouping, semantic relation and imagery effects in individuals with Down syndrome

Down syndrome (DS) is associated with a specific verbal short-term memory (STM) deficit. This study explored the effects of grouping, semantic relations and visual presentation upon verbal STM recall performance in a group of 15 individuals with DS and 15 vocabulary-matched typically developing (TD) children. Participants were presented with memoranda in either a temporally grouped schedule, such that items were grouped as pairs, or in an equally spaced presentation schedule. The two items constituting each pair were either semantically related or unrelated. Performance across these conditions was compared in verbal or verbal plus visual presentation modes. Significant memory recall benefits were observed across populations as a result of temporal grouping, semantic relations and verbal and visual combined presentation. However, a reduced benefit of semantic relation in the DS group compared to the TD group indicated that those with DS were less influenced by LTM relational knowledge. In addition, those with DS only experienced a grouping benefit during verbal and visual combined presentation, in contrast to the TD group who experienced grouping benefits throughout. This indicates that individuals with DS are poorer at encoding temporal context for purely verbal memoranda. These findings were replicated in a follow-up experiment, aimed at aligning baseline performance in the two populations. This study provides encouraging evidence that, despite their difficulties in some areas, individuals with DS can benefit from the use of grouping and LTM knowledge to assist their verbal STM performance under certain circumstances.

The role of articulatory suppression in immediate false recognition

False memory for critical lures has been widely documented in long-term memory using the Deese/Roediger-McDermott paradigm. Recent evidence suggests that false memory effects can also be found in short-term memory (STM), supporting models that assume a strong relationship between short-term and long-term memory processes. However, no study has examined the role of articulatory suppression on immediate false memory, even though phono-articulatory factors are critically involved in STM performance and are an intrinsic part of all STM accounts. The current study proposes a novel paradigm to assess false memory effects in a STM task under both silent and articulatory suppression conditions. Using immediate serial recognition, in which participants had to judge whether two successive mixed lists of six associated and non-associated words were matched, we examined true recognition of matching lists and false recognition of mismatching lists comprising a critical lure or unrelated distractor in two experiments. Results from both experiments indicated reduced true recognition of matching lists and greater false serial recognition of mismatching lists comprising a critical lure under articulatory suppression relative to silence. These findings provide further support for some current models of verbal short-term memory, which posit a strong relationship between short-term and long-term memory processes.

The interaction of word frequency and concreteness in immediate serial recall

Word frequency and word concreteness are language attributes that have been shown to independently influence the recall of items in verbal short-term memory (STM). It has been argued that such effects are evidence for the action of long-term memory knowledge on STM traces. However, research to date has not investigated whether these variables interact in serial recall. In two experiments, we examined the behavior of these variables under factorial manipulation and demonstrated that the effect of word frequency is dependent on the level of concreteness of items. Serial recall performance is examined with reference to two explanatory approaches: Walker and Hulme's (1999) dual-redintegration account and language-based models of STM. The data indicate that language-based models are more compatible with the observed effects and challenge the view that frequency and concreteness effects in STM are the products of distinct mechanisms.

Input and output modes modulate phonological and semantic contributions to immediate serial recall: evidence from a brain-damaged patient

Psycholinguistic models of short-term retention suggest that performance at verbal short-term memory (STM) tasks relies on the activation of phonological, lexical, and semantic representations, the relative impact of each depending on task variables. This was tested in normal individuals and in I.R., a brain-damaged patient with a phonological deficit. In Experiment 1, the effect of phonological and semantic similarity was assessed under different presentation formats (words, pictures) and recall modes (oral, picture pointing, and picture pointing among distractors). In Experiment 2, effects were compared using reproduction and reconstruction responses. When words were used at input, controls showed robust phonological similarity effects irrespective of response mode. In contrast, I.R. showed a reliable semantic effect. However, both studies indicated that when response mode promoted order recuperation (reconstruction and picture pointing modes), I.R. showed a typical phonological similarity effect with no semantic contribution. The data support current psycholinguistic views suggesting that the short-term retention of verbal items depends on the temporary activation of word representations. In healthy controls, presentation mode appears to modulate the role of those representations but in I.R., it was the output condition--particularly whether order was or was not required--that was found to be crucial with respect to the appearance of semantic or phonological effects. This supports the important role that order information plays in short-term memory tasks.

A quantitative and qualitative assessment of verbal short-term memory and phonological processing in 8-year-olds with a history of repetitive otitis media

Language outcome in children experiencing fluctuant hearing loss due to otitis media (OME) remains highly equivocal. In the current study, we assessed performance on highly sensitive verbal short-term memory (STM), new word learning and phonological processing tasks in 8-year-old children who had suffered from recurrent OME before the age of 3. Relative to a control group with no history of OME, we observed strictly normal performance for different STM and new word learning tasks. Performance on these tasks was also normally influenced by phonotactic, lexical and semantic variables. However, at the level of phonological processing, a small but significant decrease of performance was found in a speeded nonword identification task and a rhyme judgment task. The results of this study suggest that outcome of OME is characterized by subtle impairments at the level of perceptual-phonological analysis, but there is no significant impact on verbal STM and new word learning abilities.

LEARNING OUTCOMES

As a result of this activity, the participant will be able to (1) explain the outcome of recurrent OME before age 3 on later language and verbal STM development, (2) be aware of the complex relationships that link language development and verbal STM, (3) explain how fluctuant hearing loss during infancy and early childhood could affect verbal STM development and learning capacity for new phonological information, (4) describe different verbal STM measures that distinguish retention capacities for phonological and lexico-semantic information, and (5) explain the influence of phonotactic frequency on nonword processing in language and verbal STM tasks.

Remembering over the short-term: the case against the standard model

Psychologists often assume that short-term storage is synonymous with activation, a mnemonic property that keeps information in an immediately accessible form. Permanent knowledge is activated, as a result of on-line cognitive processing, and an activity trace is established "in" short-term (or working) memory. Activation is assumed to decay spontaneously with the passage of time, so a refreshing process-rehearsal-is needed to maintain availability. Most of the phenomena of immediate retention, such as capacity limitations and word length effects, are assumed to arise from trade-offs between rehearsal and decay. This "standard model" of how we remember over the short-term still enjoys considerable popularity, although recent research questions most of its main assumptions. In this chapter I review the recent research and identify the empirical and conceptual problems that plague traditional conceptions of short-term memory. Increasingly, researchers are recognizing that short-term retention is cue driven, much like long-term memory, and that neither rehearsal nor decay is likely to explain the particulars of short-term forgetting.