Serial Short-term Memory Research Articles

Warning—taboo words ahead! Avoiding attentional capture by spoken taboo distractors

ABSTRACT We examine whether the disruption of serial short-term memory (STM) by spoken taboo distractors is due to attentional diversion and unrelated to the underlying disruptive effect of sound on serial STM more generally, which we have argued is due to order cues arising from the automatic pre-categorical processing of acoustic changes in the sound conflicting with serial–order processing within the memory task (interference-by-process). We test whether the taboo-distractor effect is, unlike effects attributable to interference-by-process, amenable to top-down control. Experiment 1 replicated the taboo-distractor effect and showed that it is not merely a valence effect. However, promoting cognitive control by increasing focal task-load did not attenuate the effect. However, foreknowledge of the distractors did eliminate the taboo-distractor effect while having no effect on disruption by neutral words (Experiment 2). We conclude that the taboo-distractor effect results from a controllable attentional-diversion mechanism distinct from the effect of any acoustically-changing sound.

Heterogeneity of short-term memory deficits in children with dyslexia.

Many studies have highlighted short-term memory (STM) impairment in dyslexic individuals. Several studies showed deficits for both item and serial order aspects of verbal STM in dyslexic individuals. These group-based studies, however, do not inform us about the prevalence of these deficits and, importantly, their potential heterogeneity at the individual level. The present study examined both group-level and individual STM profiles in dyslexic and age-matched non-dyslexic children. While confirming previous group-based results of both item and serial order STM deficits, individual analyses indicated two distinct profiles: one profile was associated with verbal item STM and phonological impairment while another profile showed selective serial STM deficits in both verbal and visual domains. Our results highlight the need for practitioners to consider the heterogeneous nature of STM impairment in dyslexia and to adapt STM and reading treatment strategies accordingly.

Language acquisition of early sequentially bilingual children is moderated by short-term memory for order in developmental language disorder: Findings from the HelSLI study.

The role of domain-general short-term memory (STM) in language development remains controversial. A previous finding from the HelSLI study on children with developmental language disorder (DLD) suggested that not only verbal but also non-verbal STM for temporal order is related to language acquisition in monolingual children with DLD. To investigate if a similar relationship could be replicated in a sample of sequentially bilingual children with DLD. In addition to the effect of age, the effect of cumulative second language (L2) exposure was studied. Sixty-one 4-6-year-old bilingual children with DLD and 63 typically developing (TD) bilingual children participated in a cross-sectional study conducted in their L2. Children completed novel game-like tests of visual and auditory non-verbal serial STM, as well as tests of cognitive functioning and language. Interactions of STM for order with age and exposure to L2 (Finnish) were explored as explanatory variables. First, the improvement of non-verbal serial STM with age was faster in sequentially bilingual TD children than in bilingual children with DLD. A similar effect was observed for L2 exposure. However, when both age and exposure were considered simultaneously, only age was related to the differential growth of non-verbal STM for order in the groups. Second, only in children with DLD was better non-verbal serial STM capacity related to an improvement in language scores with age and exposure. The results suggest that, as previously found in Finnish monolingual children, domain-general serial STM processing is also compromised in bilingual children with DLD. Further, similar to the monolingual findings, better non-verbal serial STM was associated with greater language improvement with age and exposure, but only in children with DLD, in the age range studied here. Thus, in clinical settings, assessing non-verbal serial STM of bilingual children could improve the detection of DLD and understanding of its non-linguistic symptoms. What is already known on the subject Both phonological and non-verbal STM have been associated with DLD in monolingual and sequentially bilingual children. Monolingual children with DLD have also shown slower non-verbal serial STM development than TD children. What this study adds to existing knowledge Sequentially bilingual TD children's non-verbal serial STM improves more between ages 4 and 7 years than that of their peers with DLD, replicating a finding for monolingual children with DLD. Better non-verbal serial STM was especially associated with early receptive language development in sequentially bilingual children with DLD. L2 exposure showed largely comparable effects with age. These results support the hypothesis that a domain-general serial STM deficit is linked to DLD. What are the potential or actual clinical implications of this work? Non-verbal assessment of STM for serial order in sequentially bilingual children with DLD could benefit the development of better tailored therapeutic interventions.

Short-Term Memory for Serial Order Moderates Aspects of Language Acquisition in Children With Developmental Language Disorder: Findings From the HelSLI Study.

Previous studies of verbal short-term memory (STM) indicate that STM for serial order may be linked to language development and developmental language disorder (DLD). To clarify whether a domain-general mechanism is impaired in DLD, we studied the relations between age, non-verbal serial STM, and language competence (expressive language, receptive language, and language reasoning). We hypothesized that non-verbal serial STM differences between groups of children with DLD and typically developing (TD) children are linked to their language acquisition differences. Fifty-one children with DLD and sixty-six TD children participated as part of the HelSLI project in this cross-sectional study. The children were 4–6-year-old monolingual native Finnish speakers. They completed several tests of language and cognitive functioning, as well as new game-like tests of visual and auditory non-verbal serial STM. We used regression analyses to examine how serial STM moderates the effect of age on language. A non-verbal composite measure of serial visual and auditory STM moderated cross-sectional development of receptive language in the children with DLD. This moderation was not observed in the TD children. However, we found more rapid cross-sectional development of non-verbal serial STM in the TD children than in the children with DLD. The results suggest that children with DLD may be more likely to have compromised general serial STM processing and that superior non-verbal serial STM may be associated with better language acquisition in children with DLD.

The articulatory determinants of verbal sequence learning.

Two experiments (N = 154 in total) using the Hebb repetition effect-the enhancement of serial recall performance for a repeated sequence in among otherwise nonrepeated sequences-reveal a key role for active articulatory-planning processes in verbal sequence learning, contrary to a prominent, phonological-store based, model (Burgess & Hitch, 2006). First, Hebb sequence learning was attenuated when articulatory planning of the to-be-remembered sequence was restricted by articulatory suppression. This was less the case with auditory sequences, however, suggesting that passive perceptual organization processes operating independently of articulation also contribute to the learning of sequences presented auditorily. Second, sequence learning was enhanced for phonologically similar compared to dissimilar items when that learning was particularly reliant on articulatory planning (i.e., with visual sequences). That this enhanced learning was eliminated when articulatory planning was restricted also points to an articulatory basis for this 'phonological' similarity effect. Third, an inconsistent temporal grouping of items across instances of the repeating sequence also abolished learning but only when that grouping-based on independent evidence from output response-times during serial recall-was instantiated within an articulatory plan. These results are the first to suggest that verbal sequence learning, and not only verbal serial short-term memory (STM) performance, may be explicable by recourse to general-purpose articulatory and perceptual processes. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Supplemental Material for The Contribution of Serial Order Short-Term Memory and Long-Term Learning to Reading Acquisition: A Longitudinal Study

Supplemental Material for The Contribution of Serial Order Short-Term Memory and Long-Term Learning to Reading Acquisition: A Longitudinal Study

Distraction at the cocktail party: Attenuation of the irrelevant speech effect after a training of auditory selective attention.

Task-irrelevant auditory stimuli such as speech are known to disrupt the retention of serial information held in verbal short-term memory (STM). Although such effects of irrelevant sound are typically very robust, there is evidence suggesting that some forms of auditory distraction are susceptible to cognitive control or auditory attention. In the present study, we tested whether an extensive training of auditory selective attention reduces the degree of interference produced by irrelevant speech in a serial STM task. Participants (n = 38) were trained on an adaptive dichotic-listening task requiring selective processing of a varying list of verbal items presented via headphones while ignoring auditory distractors presented simultaneously either by a different voice or in the irrelevant ear. The number of target items that could be memorized increased throughout 5 training sessions, suggesting improvement of auditory selective attention in a dichotic-listening situation. An active control group (n = 37) was trained on an auditory duration discrimination task for 5 sessions. Prior to the training, task-irrelevant speech was shown to interfere with serial recall in both groups. After the training, however, the irrelevant speech effect was attenuated in the group that was trained on the dichotic-listening task, whereas no reduction of auditory distraction was observed in the active control group. The results show that the interference produced by task-irrelevant speech can be reduced through an extensive dichotic-listening training, suggesting that the irrelevant speech effect is susceptible to auditory selective attention. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Examining the Role of Spatial Changes in Bimodal and Uni-Modal To-Be-Ignored Stimuli and How They Affect Short-Term Memory Processes.

This study examines the potential vulnerability of short-term memory processes to distraction by spatial changes within to-be-ignored bimodal, vibratory, and auditory stimuli. Participants were asked to recall sequences of serially presented digits or locations of dots while being exposed to to-be-ignored stimuli. On unexpected occasions, the bimodal to-be-ignored sequence, vibratory to-be-ignored sequence, or auditory to-be-ignored sequence changed their spatial origin from one side of the body (e.g., ear and arm, arm only, ear only) to the other. It was expected that the bimodal stimuli would make the spatial change more salient compared to that of the uni-modal stimuli and that this, in turn, would yield an increase in distraction of serial short-term memory in both the verbal and spatial domains. Our results support this assumption as a disruptive effect of the spatial deviant was only observed when presented within the bimodal to-be-ignored sequence: uni-modal to-be-ignored sequences, whether vibratory: or auditory, had no impact on either verbal or spatial short-term memory. Implications for models of attention capture and the potential special attention capturing role of bimodal stimuli are discussed.

A semantic mismatch effect on serial recall: Evidence for interlexical processing of irrelevant speech.

Short-term memory (STM) for serially presented visual items is disrupted by task-irrelevant, to-be-ignored speech. Five experiments investigated the extent to which irrelevant speech is processed semantically by contrasting the following two hypotheses: (1) semantic processing of irrelevant speech is limited and does not interfere with serial STM or (2) irrelevant speech is routinely processed semantically at an interlexical level to allow for the detection of stimuli that are of potential relevance for the individual. We tested these hypotheses by comparing the disruption of serial recall by distractor sentences with semantically expected endings to that of sentences with semantically unexpected endings. Sentences with unexpected endings consistently produced more disruption than sentences with expected endings. Phonologically expected, but semantically unexpected endings had the same effect, demonstrating that a semantic and not a phonological mismatch is responsible for the increased disruption. In all five experiments, the semantic mismatch effect was not reduced after repeated exposure to sentences with unexpected endings. The results suggest that (1) semantic processing occurs at the interlexical level of irrelevant speech, which requires the integration of words into the sentence context and (2) the semantic content of a distractor interferes with the maintenance of serial information in short-term-memory if it is unexpected. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Postcategorical auditory distraction in short-term memory: Insights from increased task load and task type.

Task-irrelevant speech impairs short-term serial recall appreciably. On the interference-by-process account, the processing of physical (i.e., precategorical) changes in speech yields order cues that conflict with the serial-ordering process deployed to perform the serial recall task. In this view, the postcategorical properties (e.g., phonology, meaning) of speech play no role. The present study reassessed the implications of recent demonstrations of auditory postcategorical distraction in serial recall that have been taken as support for an alternative, attentional-diversion, account of the irrelevant speech effect. Focusing on the disruptive effect of emotionally valent compared with neutral words on serial recall, we show that the distracter-valence effect is eliminated under conditions-high task-encoding load-thought to shield against attentional diversion whereas the general effect of speech (neutral words compared with quiet) remains unaffected (Experiment 1). Furthermore, the distracter-valence effect generalizes to a task that does not require the processing of serial order-the missing-item task-whereas the effect of speech per se is attenuated in this task (Experiment 2). We conclude that postcategorical auditory distraction phenomena in serial short-term memory (STM) are incidental: they are observable in such a setting but, unlike the acoustically driven irrelevant speech effect, are not integral to it. As such, the findings support a duplex-mechanism account over a unitary view of auditory distraction. (PsycINFO Database Record

Registered Replication Report: Testing Disruptive Effects of Irrelevant Speech on Visual-Spatial Working Memory

<p class="p1">A Partial Replication of “Functional Equivalence of Verbal and Spatial Information in Serial Short-Term Memory (Jones, Farrand, Stuart, &amp; Morris, 1995; Experiment 4)” <p class="p1"> <p class="p1">The irrelevant speech effect (ISE)—the phenomenon that background speech impairs serial recall of visually presented material—has been widely used for examining the structure of short-term memory. In Experiment 4, Jones, Farrand, Stuart, and Morris (1995) employed the ISE to demonstrate that impairment of performance is determined by the changing-state characteristics of the material, rather than its modality of origin. The present study directly replicated the spatial condition of Experiment 4 with <em>N</em> = 40 German participants. In contrast to the original findings, no main effect of sound type was observed, <em>F</em>(2, 78) = 0.81, <em>p</em> = .450, η²<em>_p</em> = .02. The absence of an ISE in the spatial domain does not support the changing state hypothesis.

Auditory distraction by speech: Can a babble masker restore working memory performance and subjective perception to baseline?

Background speech has a detrimental impact on employees’ privacy perception and cognitive performance in open-plan offices. Sound masking that covers speech sounds can help to improve the speech privacy and the ability to work undisturbed in open office environments. Recently, non-artificial sounds such as babble or water sounds have been suggested as masking sounds because they may be perceived as more natural and subsequently less annoying. This paper compares the working memory performance and annoyance perception during background speech that was masked by different babble sounds and a waterfall sound to speech that was masked by stationary noise with the frequency spectrum of the distracting background speech signal (target speech). In a first laboratory experiment the effects of different babble sounds were compared with the noise sound at a speech-to-noise ratio of −3 dB. All subjects had to complete a serial short-term memory task and a questionnaire that covered subjective ratings. All sound conditions with masked target speech produced similar error rates and annoyance ratings as unmasked target speech. In a second laboratory experiment, the speech-to-noise ratio of target speech that was masked by babble consisting of 48 target speech signals was varied between −6 and −12 dB in steps of 3 dB. Target based babble resulted in similar error rates as stationary noise at −6 dB speech-to-noise ratio but the findings suggest that target speech that is masked by babble might even be perceived as more annoying than speech that is masked by stationary target spectrum based noise.

Metacognition in Auditory Distraction: How Expectations about Distractibility Influence the Irrelevant Sound Effect.

Task-irrelevant, to-be-ignored sound disrupts serial short-term memory for visually presented items compared to a quiet control condition. We tested whether disruption by changing state irrelevant sound is modulated by expectations about the degree to which distractors would disrupt serial recall performance. The participants’ expectations were manipulated by providing the (bogus) information that the irrelevant sound would be either easy or difficult to ignore. In Experiment 1, piano melodies were used as auditory distractors. Participants who expected the degree of disruption to be low made more errors in serial recall than participants who expected the degree of disruption to be high, independent of whether distractors were present or not. Although expectation had no effect on the magnitude of disruption, participants in the easy-to-ignore group reported after the experiment that they were less disrupted by the irrelevant sound than participants in the difficult-to-ignore group. In Experiment 2, spoken texts were used as auditory distractors. Expectations about the degree of disruption did not affect serial recall performance. Moreover, the subjective and objective distraction by irrelevant speech was similar in the easy-to-ignore group and in the difficult-to-ignore group. Thus, while metacognitive beliefs about whether the auditory distractors would be easy or difficult to ignore can have an effect on task engagement and subjective distractibility ratings, they do not seem to have an effect on the actual degree to which the auditory distractors disrupt serial recall performance.

The functional determinants of short-term memory: Evidence from perceptual-motor interference in verbal serial recall.

A functional, perceptual-motor, account of serial short-term memory (STM) is examined by investigating the way in which an irrelevant spoken sequence interferes with verbal serial recall. Even with visual list-presentation, verbal serial recall is particularly susceptible to disruption by irrelevant spoken stimuli that have the same identity as-but that are order-incongruent with-the to-be-remembered items. We test the view that such interference is because of the obligatory perceptual organization of the spoken stimuli yielding a sequence that competes with a subvocal motor-plan assembled to support the reproduction of the to-be-remembered list. In support of this view, the interference can be eliminated without changing either the identities or objective serial order of the spoken stimuli but merely by promoting a subjective perceptual organization that strips them of their order-incongruent relation to the to-be-remembered list (Experiment 1). The interference is also eliminated if subvocal motor sequence-planning is impeded via articulatory suppression (Experiment 2). The results are in line with the view that performance-limits in verbal serial STM are because of having to exploit perceptual and motor processes for purposes for which they did not evolve, not the inherently limited capacity of structures or mechanisms dedicated to storage. (PsycINFO Database Record

Attentional capture by taboo words: A functional view of auditory distraction.

It is well established that task-irrelevant, to-be-ignored speech adversely affects serial short-term memory (STM) for visually presented items compared with a quiet control condition. However, there is an ongoing debate about whether the semantic content of the speech has the capacity to capture attention and to disrupt memory performance. In the present article, we tested whether taboo words are more difficult to ignore than neutral words. Taboo words or neutral words were presented as (a) steady state sequences in which the same distractor word was repeated, (b) changing state sequences in which different distractor words were presented, and (c) auditory deviant sequences in which a single distractor word deviated from a sequence of repeated words. Experiments 1 and 2 showed that taboo words disrupted performance more than neutral words. This taboo effect did not habituate and it did not differ between individuals with high and low working memory capacity. In Experiments 3 and 4, in which only a single deviant taboo word was presented, no taboo effect was obtained. These results do not support the idea that the processing of the auditory distractors' semantic content is the result of occasional attention switches to the auditory modality. Instead, the overall pattern of results is more in line with a functional view of auditory distraction, according to which the to-be-ignored modality is routinely monitored for potentially important stimuli (e.g., self-relevant or threatening information), the detection of which draws processing resources away from the primary task. (PsycINFO Database Record

Memory as embodiment: The case of modality and serial short-term memory

Classical explanations for the modality effect—superior short-term serial recall of auditory compared to visual sequences—typically recur to privileged processing of information derived from auditory sources. Here we critically appraise such accounts, and re-evaluate the nature of the canonical empirical phenomena that have motivated them. Three experiments show that the standard account of modality in memory is untenable, since auditory superiority in recency is often accompanied by visual superiority in mid-list serial positions. We explain this simultaneous auditory and visual superiority by reference to the way in which perceptual objects are formed in the two modalities and how those objects are mapped to speech motor forms to support sequence maintenance and reproduction. Specifically, stronger obligatory object formation operating in the standard auditory form of sequence presentation compared to that for visual sequences leads both to enhanced addressability of information at the object boundaries and reduced addressability for that in the interior. Because standard visual presentation does not lead to such object formation, such sequences do not show the boundary advantage observed for auditory presentation, but neither do they suffer loss of addressability associated with object information, thereby affording more ready mapping of that information into a rehearsal cohort to support recall. We show that a range of factors that impede this perceptual-motor mapping eliminate visual superiority while leaving auditory superiority unaffected. We make a general case for viewing short-term memory as an embodied, perceptual-motor process.

Perceptual-motor determinants of auditory-verbal serial short-term memory

The role of the compatibility between obligatory perceptual organization and the active assembly of a motor-plan in auditory-verbal serial recall was examined. The classic finding that serial recall is poorer with ear-alternating items was shown to be related to spatial-source localization, thereby confirming a basic tenet of the perceptual-motor account and disconfirming an early account characterizing the two ears as separate input-channels (Experiment 1). Promoting the streaming-by-location of ear-alternating items—and therefore the incompatibility between perceived and actual order—augmented the ear-alternation effect (Experiment 2) whereas demoting streaming-by-location by reducing the regularity of the alternation attenuated it (Experiment 3). Finally, increasing the perceptual variability of an ear-alternating list while demoting the likelihood of streaming-by-location—by adding uncorrelated voice changes—also reduced the ear-alternation effect as did articulatory suppression for that part of the list (pre-recency) associated with motor-planning (Experiment 4). The results are incompatible with theories in which perceptual variability impairs serial recall due to a deficit in encoding items into a limited-capacity short-term memory space and instead point to a central role for perceptual and motor processes in serial short-term memory performance.

Distraction in verbal short-term memory: Insights from developmental differences

The contribution of two mechanisms of auditory distraction in verbal serial short-term memory—interference with the serial rehearsal processes used to support short-term recall and general attentional diversion—was investigated by exploiting differences in auditory distraction in children and adults. Experiment 1 showed that serial rehearsal plays a role in children’s as well as adults’ distractibility: Auditory distraction from irrelevant speech was greater for both children and adults as the burden on rehearsal increased. This pattern was particularly pronounced in children, suggesting that underdeveloped rehearsal skill in this population may increase their distractibility. Experiment 2 showed that both groups were more susceptible to changing- than steady-state speech when the task involved serial rehearsal—indicating that both groups suffer interference-by-process—but that children, but not adults, were also susceptible to any sort of sound (steady or changing) in a task thought to be devoid of serial rehearsal. The overall pattern of results suggests that children’s increased susceptibility to auditory distraction during verbal short-term memory performance is due to a greater susceptibility to attentional diversion; in this view, under-developed rehearsal-skill increases children’s distractibility by exacerbating their under-developed attentional control rather than by increasing interference-by-process.

Office noise: Can headphones and masking sound attenuate distraction by background speech?

Background speech is one of the most disturbing noise sources at shared workplaces in terms of both annoyance and performance-related disruption. Therefore, it is important to identify techniques that can efficiently protect performance against distraction. It is also important that the techniques are perceived as satisfactory and are subjectively evaluated as effective in their capacity to reduce distraction. The aim of the current study was to compare three methods of attenuating distraction from background speech: masking a background voice with nature sound through headphones, masking a background voice with other voices through headphones and merely wearing headphones (without masking) as a way to attenuate the background sound. Quiet was deployed as a baseline condition. Thirty students participated in an experiment employing a repeated measures design. Performance (serial short-term memory) was impaired by background speech (1 voice), but this impairment was attenuated when the speech was masked - and in particular when it was masked by nature sound. Furthermore, perceived workload was lowest in the quiet condition and significantly higher in all other sound conditions. Notably, the headphones tested as a sound-attenuating device (i.e. without masking) did not protect against the effects of background speech on performance and subjective work load. Nature sound was the only masking condition that worked as a protector of performance, at least in the context of the serial recall task. However, despite the attenuation of distraction by nature sound, perceived workload was still high - suggesting that it is difficult to find a masker that is both effective and perceived as satisfactory.

Unmasking the effects of masking on performance: The potential of multiple-voice masking in the office environment

Broadband noise is often used as a masking sound to combat the negative consequences of background speech on performance in open-plan offices. As office workers generally dislike broadband noise, it is important to find alternatives that are more appreciated while being at least not less effective. The purpose of experiment 1 was to compare broadband noise with two alternatives-multiple voices and water waves-in the context of a serial short-term memory task. A single voice impaired memory in comparison with silence, but when the single voice was masked with multiple voices, performance was on level with silence. Experiment 2 explored the benefits of multiple-voice masking in more detail (by comparing one voice, three voices, five voices, and seven voices) in the context of word processed writing (arguably a more office-relevant task). Performance (i.e., writing fluency) increased linearly from worst performance in the one-voice condition to best performance in the seven-voice condition. Psychological mechanisms underpinning these effects are discussed.