A modality congruency effect in verbal false memory

The involvement of working memory sub-systems in syllogistic reasoning problems was assessed by dual task methods. Effects of skill level and training on working memory involvement in syllogistic reasoning were examined. In Study 1, participants were pre-selected into groups of High and Low skill at syllogistic reasoning on the basis of a pencil-and-paper screening test. Six separate High and Low skill groups completed syllogistic reasoning tasks in control conditions and each group was also tested under one of the following six dual task conditions: articulatory suppression, unattended speech, verbal random generation, spatial random generation, tapping in a simple pattern, unattended pictures. The results indicated that the more skilled participants were generally following a high demand strategy, which loaded the central executive, phonological loop and imagery sub-systems, but that lower skill participants were generally following a less demanding strategy which did not load working memory components so heavily. In two Pilot Studies a training procedure was assessed and validated. In Study 2, participants were selected, on the basis of a screening test, as being unskilled at solving syllogisms but as performing above guessing level. These participants underwent the training regime validated in the Pilot Studies. Following training, separate groups of participants carried out syllogistic tests with and without one of the following four secondary tasks: articulatory suppression, unattended pictures, spatial random generation, and verbal random generation. The pattern of results indicated that training had induced high demand strategies (often logic-equivalent), which loaded the central executive and to a lesser extent the phonological loop.     

Short-term sentence recall: evidence for the contribution of acoustic-sensory information

To demonstrate that short-term sentence recall is based on conceptual and lexico-semantic information, Potter and Lombardi [J. Memory Lang. 29 (1990) 633] conducted a series of experiments using the intrusion paradigm, which combines short-term sentence recall and lexical priming. In the present paper, we employed the intrusion paradigm to demonstrate that acoustic-sensory information is involved in sentence regeneration as well. For this purpose, we presented sentences visually for silent reading (conceptual and phonological information) and reading aloud (conceptual, phonological, and--in addition--acoustic-sensory information). We demonstrated that less intrusions appeared in the reading aloud condition. This effect supports the assumption that, if available, acoustic-sensory information contributes to the regeneration process.     

Automatic semantic encoding in verbal short-term memory: Evidence from the concreteness effect

The concreteness effect in verbal short-term memory (STM) tasks is assumed to be a consequence of semantic encoding in STM, with immediate recall of concrete words benefiting from richer semantic representations. We used the concreteness effect to test the hypothesis that semantic encoding in standard verbal STM tasks is a consequence of controlled, attention-demanding mechanisms of strategic semantic retrieval and encoding. Experiment 1 analysed the effect of presentation rate, with slow presentations being assumed to benefit strategic, time-dependent semantic encoding. Experiments 2 and 3 provided a more direct test of the strategic hypothesis by introducing three different concurrent attention-demanding tasks. Although Experiment 1 showed a larger concreteness effect with slow presentations, the following two experiments yielded strong evidence against the strategic hypothesis. Limiting available attention resources by concurrent tasks reduced global memory performance, but the concreteness effect was equivalent to that found in control conditions. We conclude that semantic effects in STM result from automatic semantic encoding and provide tentative explanations for the interaction between the concreteness effect and the presentation rate.     

Conceptual similarity effects on working memory in sentence contexts: Testing a theory of anaphora

The degree of semantic similarity between an anaphoric noun phrase (e.g., the bird) and its antecedent (e.g., a robin) is known to affect the anaphor resolution process, but the mechanisms that underlie this effect are not known. One proposal (Almor, 1999) is that semantic similarity triggers interference effects in working memory and makes two crucial assumptions: First, semantic similarity impairs working memory just as phonological similarity does (e.g., Baddeley, 1992), and, second, this impairment interferes with processes of sentence comprehension. We tested these assumptions in two experiments that compared recall accuracy between phonologically similar, semantically similar, and control words in sentence contexts. Our results do not provide support for Almor's claims: Phonological overlap decreased recall accuracy in sentence contexts, but semantic similarity did not. These results shed doubt on the idea that semantic interference in working memory is an underlying mechanism in anaphor resolution.     

Gummed-up memory: Chewing gum impairs short-term recall

Several studies have suggested that short-term memory is generally improved by chewing gum. However, we report the first studies to show that chewing gum impairs short-term memory for both item order and item identity. Experiment 1 showed that chewing gum reduces serial recall of letter lists. Experiment 2 indicated that chewing does not simply disrupt vocal–articulatory planning required for order retention: Chewing equally impairs a matched task that required retention of list item identity. Experiment 3 demonstrated that manual tapping produces a similar pattern of impairment to that of chewing gum. These results clearly qualify the assertion that chewing gum improves short-term memory. They also pose a problem for short-term memory theories asserting that forgetting is based on domain-specific interference given that chewing does not interfere with verbal memory any more than tapping. It is suggested that tapping and chewing reduce the general capacity to process sequences.     

Presentation modality and mode of recall in verbal false memory

False memories were investigated for aurally and visually presented lists of semantically associated words. In Experiment 1, false written recall of critical intrusions was reliably lower following visual presentation compared with aural presentation. This presentation modality effect was attributed to the use of orthographic features during written recall to edit critical intrusions from visually presented lists. As predicted by this hypothesis, the modality effect was eliminated when the mode of recall was spoken rather than written. In Experiment 2, the modality effect in written recall was again replicated and then eliminated with an orienting task that ensured orthographic encoding even of aurally presented words. Thus, the modality effect appears to depend on using orthographic information to distinguish true from false verbal memories.     

Syntax and serial recall: How language supports short-term memory for order

The extent to which familiar syntax supports short-term serial recall of visually presented six-item sequences was shown by the superior recall of lists in which item pairs appeared in the order of “adjective–noun” (items 1–2, 3–4, 5–6)—congruent with English syntax—compared to when the order of items within pairs was reversed. The findings complement other evidence suggesting that short-term memory is an assemblage of language processing and production processes more than it is a bespoke short-term memory storage system.     

Modality independence of order coding in working memory: Evidence from cross-modal order interference at recall

Working memory researchers do not agree on whether order in serial recall is encoded by dedicated modality-specific systems or by a more general modality-independent system. Although previous research supports the existence of autonomous modality-specific systems, it has been shown that serial recognition memory is prone to cross-modal order interference by concurrent tasks. The present study used a serial recall task, which was performed in a single-task condition and in a dual-task condition with an embedded memory task in the retention interval. The modality of the serial task was either verbal or visuospatial, and the embedded tasks were in the other modality and required either serial or item recall. Care was taken to avoid modality overlaps during presentation and recall. In Experiment 1, visuospatial but not verbal serial recall was more impaired when the embedded task was an order than when it was an item task. Using a more difficult verbal serial recall task, verbal serial recall was also more impaired by another order recall task in Experiment 2. These findings are consistent with the hypothesis of modality-independent order coding. The implications for views on short-term recall and the multicomponent view of working memory are discussed.     

Serial reconstruction of order and serial recall in verbal short-term memory

We carried out a series of experiments on verbal short-term memory for lists of words. In the first experiment, participants were tested via immediate serial recall, and word frequency and list set size were manipulated. With closed lists, the same set of items was repeatedly sampled, and with open lists, no item was presented more than once. In serial recall, effects of word frequency and set size were found. When a serial reconstruction-of-order task was used, in a second experiment, robust effects of word frequency emerged, but set size failed to show an effect. The effects of word frequency in order reconstruction were further examined in two final experiments. The data from these experiments revealed that the effects of word frequency are robust and apparently are not exclusively indicative of output processes. In light of these findings, we propose a multiple-mechanisms account in which word frequency can influence both retrieval and preretrieval processes.     

Working memory capacity and the spacing effect in cued recall

Spacing repetitions typically improves memory (the spacing effect). In three cued recall experiments, we explored the relationship between working memory capacity and the spacing effect. People with higher working memory capacity are more accurate on memory tasks that require retrieval relative to people with lower working memory capacity. The experiments used different retention intervals and lags between repetitions, but were otherwise similar. Working memory capacity and spacing of repetitions both improved memory in most of conditions, but they did not interact, suggesting additive effects. The results are consistent with the ACT-R model’s predictions, and with a study-phase recognition process underpinning the spacing effect in cued recall.     

Orthographic congruency effects in the suprasegmental domain: Evidence from Thai

The influence of orthographic knowledge on lexical tone processing was examined by manipulating the congruency between the tone and the tone marker of Thai monosyllabic words presented in three metalinguistic tasks. In tone monitoring (Experiment 1) and same–different tone judgement (Experiment 2)—that is, tasks that require an explicit analysis of tone information—an orthographic congruency effect was observed: Better performance was found when both tone and tone marker led to the same response than when they led to opposite, competing responses. In rhyme judgement (Experiment 3), a metaphonological task that allows tone to be processed in a more natural way since it does not require explicit analysis of tone, the orthographic effect emerged only when the interstimulus interval was lengthened from 30 to 1,200 ms. In addition to demonstrating the generalization of the orthographic congruency effect to the suprasegmental domain in Thai, the present data also suggest relatively late and task-dependent activation of orthographic representations of tone.     

Suffix effects and probe modality in probed recall: Implications for readout from sensory memory

The effect of a redundant stimulus suffix was investigated in three experiments using a probed recall task. The probe modality was auditory in the first experiment and visual in the second. In the third experiment, both probe modalities were tested. The presentation rate was varied in all three experiments and was confounded with the delay of the suffix. The suffix was found to have a small and approximately equal effect on the last six serial positions. In contrast to the predictions from Crowder and Morton's (1969) PAS model, presentation rate and suffix delay did not interact with the suffix effect. The results indicate that at least six items can be simultaneously represented in PAS, that there is no appreciable decay of information from PAS during presentation of the last list items, and that readout of PAS information does not occur either during list presentation or between the end of list presentation and the beginning of overt report.     

The ineluctable modality of the audible: perceptual determinants of auditory verbal short-term memory

Classical cognitive accounts of verbal short-term memory (STM) invoke an abstract, phonological level of representation which, although it may be derived differently via different modalities, is itself amodal. Key evidence for this view is that serial recall of phonologically similar verbal items (e.g., the letter sounds b, c, g, and d) is worse than that of dissimilar items, regardless of modality of presentation. Here we show that the effect of such phonological similarity in STM can be fully accounted for by the joint action of articulatory similarity, leading to errors in speech planning processes, and acoustic similarity within auditorily presented lists, which modulates their perceptual organization. The results indicate that key evidence used to argue for the existence of abstract phonological representation can in fact be fully accounted for by reference to modality-specific perceptual and motor planning mechanisms.     

Syntactic priming in Chinese sentence comprehension: Evidence from Event-Related Potentials

Using the event-related potential (ERP) technique, this study examined the nature of syntactic priming effects in Chinese. Participants were required to read prime-target sentence pairs each embedding an ambiguous relative clause (RC) containing either the same verb or a synonymous verb. In Chinese, the word de serves as a relative clause marker. During reading a potential Chinese RC structure (either the prime or the target sentence), Chinese readers initially expect to read an Subject–Verb–Object (SVO) structure but the encounter of a relative clause marker de would make readers abandon the initial strategy and reanalyze the structure as a relative clause. A reduced P600 effect was elicited by the critical word de in the target sentence containing the same initial verb as in the prime sentence. No significant reduction of the P600 was observed in the target sentences in the synonymous condition. The results demonstrated that verb repetition but not similarity in meaning produced a syntactic priming effect in Chinese. The constraint-based lexicalist hypothesis and the argument structure theory were adopted to explain the syntactic priming effect obtained in the current study.     

Phonological similarity and lexicality effects in children's verbal short-term memory: concerns about the interpretation of probed recall data

Probed recall tasks are often used to assess aspects of children's verbal short-term memory development because they are not subject to potentially confounding output effects. However, the marked recency effects that are observed in probed recall means that these tasks are potentially insensitive to experimental manipulations when later serial positions are probed. This clouds the interpretation of data from probed recall studies in which children of different ages are presented with to-be-remembered lists of different lengths. In two experiments we examined the magnitude of phonological similarity and lexicality effects in both 5- to 6- and 8- to 9-year-old children. In each case performance on probed recall tasks was contrasted with that seen on tests of serial recognition. The results indicated that probed recall tasks are potentially less sensitive to experimental manipulations in younger than older children. However, comparable effects of both phonological similarity and lexicality were seen in both age groups using serial recognition procedures. These findings have implications for the interpretation of other studies that have examined the development of verbal short-term memory using probed recall and for theoretical accounts of the development of phonological similarity and lexicality effects in children.     

Phonological similarity and lexicality effects in children's verbal short-term memory: Concerns about the interpretation of probed recall data

Probed recall tasks are often used to assess aspects of children's verbal short-term memory development because they are not subject to potentially confounding output effects. However, the marked recency effects that are observed in probed recall means that these tasks are potentially insensitive to experimental manipulations when later serial positions are probed. This clouds the interpretation of data from probed recall studies in which children of different ages are presented with to-be-remembered lists of different lengths. In two experiments we examined the magnitude of phonological similarity and lexicality effects in both 5- to 6- and 8- to 9-year-old children. In each case performance on probed recall tasks was contrasted with that seen on tests of serial recognition. The results indicated that probed recall tasks are potentially less sensitive to experimental manipulations in younger than older children. However, comparable effects of both phonological similarity and lexicality were seen in both age groups using serial recognition procedures. These findings have implications for the interpretation of other studies that have examined the development of verbal short-term memory using probed recall and for theoretical accounts of the development of phonological similarity and lexicality effects in children.     

Retroactive effects of irrelevant speech on serial recall from short-term memory

The authors report 5 serial-recall experiments. In 4 of the 5 experiments, they show that irrelevant sound (IS) has a retroactive effect on material already in memory. In Experiment 1, IS presented during a filled retention interval had a reliable effect on list recall. Four further experiments, 3 of which used retroactive IS, showed that IS continued to-have an effect on recall following a long, filled retention interval. Articulatory suppression during visual input was found to abolish the long-lasting, retroactive effect of IS, supporting the idea that IS affects the phonological-loop component of short-term memory. IS also, therefore, seems to affect a longer term memory system with which the loop interacts.     

Context effects in short-term memory: confirmatory evidence from recall of visually presented lists

Thirty-two subjects had tests of serial recall of visually presented nine-digit lists which were either presented in a single block of trials (constant context) or in between lists of much longer length (variable context). Other variables were vocalization-during-presentation versus silent memorization (within subject) and order of recall (between subjects). The results showed a negative effect of variable context on the penultimate serial positions in the case of silent memorization but not in the case of vocalization. Context had no effect on the first and middle parts of the list, which confirms earlier results with auditorily presented lists (Bunt 1976), but which disagrees with the original evidence from Crowder (1969). Subjects preferred forward recall in the case of silent memorization and echobox recall in the case of vocalization during presentation, irrespective of context.

The results are discussed within the framework of the notion of precategorical acoustic storage (PAS) and of positional retrieval cues. The latter theory seems to provide a better and more comprehensive account.