Serial Recall Research Articles

Children’s suffix effects for verbal working memory reflect phonological coding and perceptual grouping

When listeners recall order of presentation for sequences of unrelated words, recall is most accurate for first and final items. When a speech suffix is appended to the list, however, the advantage for final items is diminished. The usual interpretation is that listeners recover phonological structure from speech signals and use that structure to store items in a working memory buffer; the process of recovering phonological structure for a suffix interrupts that processing for the final list item. Although not mutually exclusive, another hypothesis suggests that perceptual grouping of list items and suffix based on common acoustic structure is necessary for the effect to occur. To evaluate these accounts as well as potential age-related differences, adults and 8-year-old children were asked to recall order of presentation for a closed set of nouns in five suffix conditions: none, auditory go, lipread go, a tone, and a colored circle. Overt articulation was prohibited, but attention to the suffix was mandated. Children’s serial recall was generally poorer than that of adults, but patterns across list positions were similar for both age groups. Participants showed stronger effects for speech suffixes than for nonspeech suffixes regardless of whether suffixes were seen or heard, but effects were not restricted to final list items. And although effects of heard and lipread suffixes were similar for early list items, heard speech exerted greater effects on late list items. Outcomes suggest that some effect of heard and lipread speech suffixes arises from their shared phonological structure, but this effect is strongest when perceptual grouping occurs.

The effects of Hebb repetition learning and temporal grouping in immediate serial recall of spatial location.

The Hebb repetition effect is a phenomenon in which a repeated presentation of the same list increases the performance in immediate serial recall. This provided the theoretical basis for a core assumption of the Atkinson and Shiffrin model regarding information transfer from short-term memory to long-term memory. The Hebb repetition effect was originally reported for the verbal domain, but subsequent studies found similar phenomena using visuospatial paradigms, for example, in serial-order memory for dot locations. The present study examined in two experiments the effects of presentation timing of nine spatial locations on Hebb repetition learning. In Experiment 1, the Hebb repetition effects were observed for spatial locations with constant timing presentation as well as temporal grouping presentation. In the latter condition, all lists were presented with the same temporal structure, that is, temporal pauses were inserted after the third and sixth serial positions. This manipulation led to a better recall performance in comparison with the constant presentation, but did not interact with the repetition. In Experiment 2, the Hebb list was presented with a different temporal structure in every repetition in the random-grouping condition. Although this manipulation is known to eliminate or weaken the Hebb effect in the verbal domain, we observed stable repetition effects in this experiment. This suggests that there might be some domain-specific mechanisms in Hebb repetition learning. These results may facilitate the development of theories of the relationship between short-term and long-term memory.

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).

Can short-term memory be trained?

Is the capacity of short-term memory fixed, or does it improve with practice? It is already known that training on complex working memory tasks is more likely to transfer to untrained tasks with similar properties, but this approach has not been extended to the more basic short-term memory system responsible for verbal serial recall. Here we investigated this with adaptive training algorithms widely applied in working memory training. Serial recall of visually presented digits was found to improve over the course of 20 training sessions, but this improvement did not extend to recall of either spoken digits or visually presented letters. In contrast, training on a nonserial visual short-term memory color change detection task did transfer to a line orientation change detection task. We suggest that training only generates substantial transfer when the unfamiliar demands of the training activities require the development of novel routines that can then be applied to untrained versions of the same paradigm (Gathercole, Dunning, Holmes, & Norris, 2019). In contrast, serial recall of digits is fully supported by the existing verbal short-term memory system and does not require the development of new routines.

How do we perform backward serial recall?

Following Conrad (1965, Journal of Verbal Learning and Verbal Behavior, 4, 161–169) it is often assumed that backward verbal serial recall is performed by repeated forward scans through the list and then recalling the last remaining item. Direct evidence for this peel-off strategy is relatively weak, and there has to date been no examination of its potential role in the recall of spatial sequences. To examine the role of this strategy in both verbal and spatial domains, two experiments examined response output times for forward and backward recall. For spatial span, the pattern of timing was the same in both directions. For digit span, backward recall was considerably slower. This was true whether responses were made by means of manual selection on a keyboard display (Experiment 1) or were spoken (Experiment 2a). Only two of 24 participants showed signs of using a peel-off strategy in spoken backward recall. Peel-off was not a dominant strategy in backward digit recall and there was no indication that it was ever used for spatial stimuli. Most participants reported using a combination of different strategies. In Experiment 2b, four further participants were directly instructed to use a peel-off strategy. The pattern of response times for three of these individuals was similar to the two participants from Experiment 2a previously identified as using peel-off. We conclude that backward recall can be performed using many strategies, but that the peel-off is rarely used spontaneously.

Altered transposition asymmetry in serial ordering in early Parkinson's disease

IntroductionThe ability to arrange thoughts and actions in an appropriate serial order is impaired in Parkinson's disease (PD). However, it is unclear how serial order is represented and manipulated and how the representation or manipulation is altered in the early stages of PD. We aimed to analyze the pattern of performance errors in serial ordering versus serial recall in nondemented PD patients with mild clinical symptoms and healthy adults to identify the underlying principles of serial ordering. MethodsPD patients (N = 57) and healthy controls (N = 40) completed the adaptive digit ordering and digit span forward tests. We focused on items recalled in incorrect positions (transposition) and analyzed the tendency to recall transposed items too early (anticipation) versus too late (postponement). We also analyzed the tendency to recall the item displaced by the error (fill-in) versus the item following the error in the target output order (infill) after anticipation errors. ResultsPD patients not only made more transposition errors but also showed distinct error patterns. The patients made more anticipations but not postponements, and more fill-ins but not in fills than healthy controls in the ordering test (transposition asymmetry). Individual patients' percentage of anticipations was negatively correlated with their daily exposure to D2/3 receptor agonists. Patients’ error pattern in the forward test was normal. ConclusionThe increase in anticipations in PD suggests an increase in the forward-specific variability in the representation of serial order. Their increase in fill-ins suggests a deficit in the chaining mechanism involved in the manipulation of serial order.

Literacy improves short-term serial recall of spoken verbal but not visuospatial items – Evidence from illiterate and literate adults

It is widely accepted that specific memory processes, such as serial-order memory, are involved in written language development and predictive of reading and spelling abilities. The reverse question, namely whether orthographic abilities also affect serial-order memory, has hardly been investigated. In the current study, we compared 20 illiterate people with a group of 20 literate matched controls on a verbal and a visuospatial version of the Hebb paradigm, measuring both short- and long-term serial-order memory abilities. We observed better short-term serial-recall performance for the literate compared with the illiterate people. This effect was stronger in the verbal than in the visuospatial modality, suggesting that the improved capacity of the literate group is a consequence of learning orthographic skills. The long-term consolidation of ordered information was comparable across groups, for both stimulus modalities. The implications of these findings for current views regarding the bi-directional interactions between memory and written language development are discussed.

Visual Hebb Repetition Effects: The Role of Psychological Distinctiveness Revisited.

Across two experiments we investigate the role of psychological distinctiveness on the Hebb repetition effect. In direct contradiction to Horton et al. (2008), Experiment 1 demonstrated the Hebb repetition effect for inverted faces. Importantly, the Hebb repetition effect was evident only when the filler and Hebb sequences comprised different items (no-stimulus-overlap) and was abolished when the filler and Hebb trials comprised the same items (full-stimulus-overlap). Experiment 2 further examined the impact of psychological distinctiveness on the Hebb repetition effect by comparing serial recall for upright unfamiliar-faces, inverted unfamiliar-faces, and abstract matrices. We demonstrate the visual Hebb repetition effect for stimuli that possess both purportedly high (upright faces) and low (inverted faces and matrices) levels of psychological distinctiveness. The findings of both experiments contradict the earlier claim (Horton et al., 2008) that stimuli possessing low levels of psychological distinctiveness do not show the visual Hebb repetition effect. However, we further highlight the importance of stimulus overlap between filler and Hebb sequences in determining the visual Hebb repetition effect. More generally, our findings emphasize that the Hebb repetition effect is a common feature of memory across different stimulus types.

Verbal working memory and linguistic long-term memory: Exploring the lexical cohort effect.

Numerous studies have shown that verbal working memory (vWM) performance is strongly influenced by linguistic knowledge, with items more familiar at sublexical, lexical, and/or semantic levels leading to higher vWM recall performance. Among the many different psycholinguistic variables whose impact on vWM has been studied, the lexical cohort effect is one of the few effects that has not yet been explored. The lexical cohort effect reflects the fact that words sharing their first phonemes with many other words (e.g. alcove, alligator, alcohol…) are typically responded to more slowly as compared to words sharing their first phonemes with a smaller number of words. In a pilot experiment (Experiment 1), we manipulated the lexical cohort effect in an immediate serial recall task and found no effect. Experiment 2 showed that, in a lexical decision task, participants responded more quickly to items stemming from small cohorts, showing that the material used in Experiment 1 allowed for a valid manipulation of the cohort effect. Experiment 3, using stimuli from Experiment 2 associated with maximal cohort effects during lexical decision, failed again to reveal a cohort effect in an immediate serial recall task. We argue that linguistic knowledge impacts vWM performance via continuous interactive activation within the linguistic system, which is not the case for the lexical cohort variable that may influence language processing only at the initial stages of stimulus activation.

Associations Between Hypernasality, Intelligibility, and Language and Reading Skills in 10-Year-Old Children With a Palatal Cleft.

This study investigated the associations between hypernasality and intelligibility, and language and reading skills in 10-year old children with a cleft palate ± lip. Cross-sectional data collected during routine assessments of speech and language in a centralized treatment setting. Children aged 10, born with cleft palate ± lip from 4 birth cohorts (N = 123). Hypernasality and intelligibility: Swedish Articulation and Nasality Test-N; language: Language 6-16 (Sentence recall, Serial recall, Vocabulary); reading: word chain test and reading comprehension test. A total of 71.3% of the children had no occurrence of hypernasality and 82.8% had intelligibility scores within the normal range. For all children with hypernasality and intelligibility within the normal range, reading and language scores were also within normal ranges. Children with presence of hypernasality had significantly lower language skills, with mean scores within the lower normal range. Children with reduced intelligibility had lower scores on reading comprehension. The findings highlight a possible association between hypernasality and language skills, and intelligibility and reading skills. Cleft teams should consider routine assessments of language and reading skills in children with speech impairment, in order to identify potential needs for intervention as early as possible.

Is auditory distraction by changing-state and deviant sounds underpinned by the same mechanism? Evidence from pupillometry

The mere presence of task-irrelevant auditory stimuli is known to interfere with cognitive functioning. Disruption can be caused by changing auditory distractors (the changing-state effect) or by a sound that deviates from the auditory background (the deviation effect). The unitary account of auditory distraction explains both phenomena in terms of attentional capture whereas the duplex-mechanism account posits that they reflect two fundamentally different forms of distraction in which only the deviation effect is caused by attentional capture. To test these predictions, we exploited a physiological index of attention orienting: the pupillary dilation response (PDR). Participants performed visual serial recall while ignoring sequences of spoken letters. These sequences either comprised repeated or changing letters, and one letter could sometimes be replaced by pink noise (the deviant). Recall was poorer in both changing-state and deviant trials. Interestingly, the PDR was elicited by deviant sounds but not changing-state sounds, while a tonic increase in pupil size was found throughout changing-state trials. This physiological dissociation of the changing-state and the deviation effects suggests they are subtended by distinct mechanisms thereby procuring support for the duplex-mechanism account over the unitary account.

Control processes in short-term storage: Retrieval strategies in immediate recall depend upon the number of words to be recalled.

According to the Atkinson and Shiffrin (1968) model, control processes in the short-term memory store determine the selection of different storage, search, and retrieval strategies. Although rehearsal is the most studied short-term control process, it is necessary to specify the different retrieval strategies available for participants to use in searching for and outputting from short-term or immediate memory, as well as the degree to which participants can flexibly select different retrieval strategies for recalling rehearsed and unrehearsed materials. In three experiments we examined retrieval strategies in tests of immediate free recall (Exp. 1), immediate serial recall (ISR; Exp. 2), and a variant of ISR that we call ISR-free (Exp. 3). In each experiment, participants were presented with very short lists of four, five, or six words and were instructed to recall one, two, three, or all of the items from each list. Neither the list length nor the number of to-be-recalled items was known in advance. The serial position of the first item recalled in all three tasks depended on the number of to-be-recalled items. When only one or two items were to be recalled, participants tended to initiate recall with the final or penultimate list item, respectively; when participants were required to recall as many list items as possible, they tended to initiate recall with the first list item. These findings show that different retrieval strategies exist for rapidly searching for different numbers of items from immediate memory, and they confirm that participants have some control over their output order, as measured by the first items recalled.

The Effects of Acute Exercise on Episodic Memory Subtypes: Free, Cued, Serial Recall and Recognition

The objective of this study was to comprehensively evaluate the experimental effects of acute moderate-intensity aerobic exercise on various episodic memory subtypes, including free, cued, serial recall and recognition. We employed a two-arm, between-subject randomized controlled experiment (Mage=20 y; N=20 per group), with participants engaging in a 15-minute moderate-intensity bout of aerobic exercise or engaged in a time-matched seated task. Free (including short- and long-term), cued, and recognition were assessed using the Buscheke Selective Reminding Task (BSRT), whereas serial recall was assessed using the Sentence Repetition Test (SRT). For immediate recall (5.95 vs. 6.00), total recall (11.68 vs. 11.57), number of trials to obtain 3 perfect trials from the BSRT (10.89 vs. 10.90), cued recall (9.16 vs. 10.05), recognition (12.0 vs. 12.0), delayed free recall (10.68 vs. 10.57) and serial recall (15.26 vs. 16.10), scores were not statistically significantly different (all P’s > .05) between the exercise and control groups. In this experiment we comprehensively evaluated the effects of acute moderate-intensity exercise on free, cued, serial recall and memory recognition. We did not observe any enhancement or detrimental effects of acute exercise on episodic memory function. Additional work is needed to disentangle the complex relationship between exercise and memory function, and in particular, evaluate potential moderators (e.g., sex, fitness level) of this paradigm.

Variations in the Beneficial Effects of Spatial Structure and Serial Organisation on Working Memory Span in Humans and Other Species.

This chapter reviews studies of spontaneous search in large-scale settings and studies featuring variations of the Corsi test in humans and animals. It aims to highlight a synergy of working memory (WM) processes and the use of spatio-temporal structure and explain its underpinnings within a comparative framework. The chapter starts by showing that the degree of organisation of serial search patterns spontaneously deployed by humans and animals in simulated foraging tasks is associated with a reduction of WM errors. Then, by comparing studies conducted on different species, it exposes a parallel between the degree of search organisation and taxonomic relatedness to humans. Such a parallel could indicate that a hallmark of the cognition of humans and closely related species is the ability to offload WM by developing serially organised search patterns that exploit the spatial structure of the environment. However, a causal relationship between serial organisation and search efficiency can only be inferred with serial recall tasks, where the structure of specific sequences can be systematically manipulated. Thus, studies using variations of the Corsi test are considered subsequently, which suggest that humans might enjoy an exceptional aptitude to benefit from the spatio-temporal structure in serial tasks, despite remarkable memory abilities shown by other primate species as well. The extent to which the benefit of spatial organisation in human WM span must be mediated by perceptual grouping processes is then considered. To clarify this issue, recent experiments using virtual reality to compare serial recall in small visual displays that afford perceptual grouping and in immersive navigational spaces that cannot do so are discussed. The results of these latter experiments indicate that the effects of structure in serial recall emerge in conditions not affording grouping at perceptual level. Thus, it is suggested that more central representational processes play a role in the interaction between spatio-temporal organisation and working memory span in humans.

Interactions Between Item Set and Vocoding in Serial Recall.

Serial recall of digits is frequently used to measure short-term memory span in various listening conditions. However, the use of digits may mask the effect of low quality auditory input. Digits have high frequency and are phonologically distinct relative to one another, so they should be easy to identify even with low quality auditory input. In contrast, larger item sets reduce listener ability to strategically constrain their expectations, which should reduce identification accuracy and increase the time and/or cognitive resources needed for identification when auditory quality is low. This diminished accuracy and increased cognitive load should interfere with memory for sequences of items drawn from large sets. The goal of this work was to determine whether this predicted interaction between auditory quality and stimulus set in short-term memory exists, and if so, whether this interaction is associated with processing speed, vocabulary, or attention. We compared immediate serial recall within young adults with normal hearing across unprocessed and vocoded listening conditions for multiple stimulus sets. Stimulus sets were lists of digits (1 to 9), consonant-vowel-consonant (CVC) words (chosen from a list of 60 words), and CVC nonwords (chosen from a list of 50 nonwords). Stimuli were unprocessed or vocoded with an eight-channel noise vocoder. To support interpretation of responses, words and nonwords were selected to minimize inclusion of multiple phonemes from within a confusion cluster. We also measured receptive vocabulary (Peabody Picture Vocabulary Test [PPVT-4]), sustained attention (test of variables of attention [TOVA]), and repetition speed for individual items from each stimulus set under both listening conditions. Vocoding stimuli had no impact on serial recall of digits, but reduced memory span for words and nonwords. This reduction in memory span was attributed to an increase in phonological confusions for nonwords. However, memory span for vocoded word lists remained reduced even after accounting for common phonetic confusions, indicating that lexical status played an additional role across listening conditions. Principal components analysis found two components that explained 84% of the variance in memory span across conditions. Component one had similar load across all conditions, indicating that participants had an underlying memory capacity, which was common to all conditions. Component two was loaded by performance in the vocoded word and nonword conditions, representing the sensitivity of memory span to vocoding of these stimuli. The order in which participants completed listening conditions had a small effect on memory span that could not account for the effect of listening condition. Repetition speed was fastest for digits, slower for words, and slowest for nonwords. On average, vocoding slowed repetition speed for all stimuli, but repetition speed was not predictive of individual memory span. Vocabulary and attention showed no correlation with memory span. Our results replicated previous findings that low quality auditory input can impair short-term memory, and demonstrated that this impairment is sensitive to stimulus set. Using multiple stimulus sets in degraded listening conditions can isolate memory capacity (in digit span) from impaired item identification (in word and nonword span), which may help characterize the relationship between memory and speech recognition in difficult listening conditions.

Effect of Foreign Accent on Immediate Serial Recall.

This study disentangled factors contributing to impaired memory for foreign-accented words - misperception and disruption of encoding. When native English and Cantonese-accented words were presented auditorily for serial recall (Experiment 1), intrusion errors for accented words were higher across all serial positions (SPs). Participants made more intrusion errors during auditory presentation than visual and auditory presentation, and more errors for accented words than native words. Lengthening the interstimulus intervals in Experiment 2 reduced intrusion, repetition, order, and omission errors in the middle and late SPs during accented word recall, suggesting that extra time is required for identification and encoding of accented words into memory. Analyses of the intrusions showed that a majority of them were misperceptions and sounded similar to the stimulus words. These findings suggest that effortful perceptual processing of accented speech can induce perceptual difficulty and interfere with downstream memory processes by exhausting the shared pool of working memory.

The resilience of verbal sequence learning: Evidence from the Hebb repetition effect.

In a single large-scale study, we demonstrate that verbal sequence learning as studied using the classic Hebb repetition effect (Hebb, 1961)-the improvement in the serial recall of a repeating sequence compared to nonrepeated sequences-is resilient to both wide and irregular spacing between sequence repetitions. Learning of a repeated sequence of letters was evident to a comparable degree with three, five, and eight intervening nonrepeated sequences and regardless of whether the spacing between repetitions was regular or irregular. Importantly, this resilience of verbal sequence learning was observed despite complete item-set overlap between repeated and nonrepeated sequences. The findings are consistent with the conceptualization of the Hebb repetition effect as a laboratory analogue of natural phonological word-form learning. The results also have implications for the two leading models of Hebb sequence learning: Whereas the results are incompatible with the model of Page and Norris (2009), they can be handled readily by the model of Burgess and Hitch (2006) through the abandonment of its assumption of long-term (across-trial level) decay. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Re-assessing the relation of phonological short-term memory and single word production

Re-assessing the relation of phonological short-term memory and single word production

Set size and long-term memory/lexical effects in immediate serial recall: Testing the impurity principle.

The impurity principle (Surprenant & Neath, 2009b) states that because memory is fundamentally reconstructive, tasks and processes are not pure. This principle is based on a long line of research showing the effects of one memory system or process on another. Although the principle is widely accepted, many researchers appear hesitant to endorse it in extreme edge cases. One such case involves the effects of long-term memory and lexical factors when a small, closed set of items is used. According to this view, because the subject knows the set of items, there will be no effect of item information. In contrast, the impurity principle predicts that such effects can still be observed, because immediate serial recall with a small closed set of items is not a pure test of order information. Four experiments tested this edge case. In Experiments 1 and 2, we found concreteness effects when item uncertainty was minimized in both within-subjects (Exp. 1) and between-subjects (Exp. 2) designs. In Experiments 3 and 4, we found frequency effects when item uncertainty was minimized in both within-subjects (Exp. 3) and between-subjects (Exp. 4) designs. Analyses of intrusion and omission errors indicated that the sets of items had been learned. Analyses by experiment half also confirmed that the effects of concreteness and frequency were observable in the latter stages of the experiments, when there should have been even less doubt about the items. The results support the impurity principle and suggest that hesitation about accepting it in edge cases is unwarranted.

Working memory training involves learning new skills.

We present a new framework characterizing training-induced changes in WM as the acquisition of novel cognitive routines akin to learning a new skill. Predictions were tested in three studies analyzing the transfer between WM tasks following WM training. Study 1 reports a meta-analysis establishing substantial transfer when trained and untrained tasks shared either a serial recall, complex span or backward span paradigm. Transfer was weaker for serial recall of verbal than visuo-spatial material, suggesting that this paradigm is served by an existing verbal STM system and does not require a new routine. Re-analysis of published WM training data in Study 2 showed that transfer was restricted to tasks sharing properties proposed to require new routines. In a re-analysis of data from four studies, Study 3 demonstrated that transfer was greatest for children with higher fluid cognitive abilities. These findings suggest that development of new routines depends on general cognitive resources and that they can only be applied to other similarly-structured tasks.