Memory Span In Children Research Articles

Background Speech Disrupts Working Memory Span in 5-Year-Old Children

The present study tested the effects of background speech and nonspeech noise on 5-year-old children's working memory span. Five-year-old typically developing children (range = 58.6 to 67.6 months; n = 94) completed a modified version of the Missing Scan Task, a missing-item working memory task, in quiet and in the presence of two types of background noise: male two-talker speech and speech-shaped noise. The two types of background noise had similar spectral composition and overall intensity characteristics but differed in whether they contained verbal content. In Experiments 1 and 2, children's memory span (i.e., the largest set size of items children successfully recalled) was subjected to analyses of variance designed to look for an effect of listening condition (within-subjects factor: quiet, background noise) and an effect of background noise type (between-subjects factor: two-talker speech, speech-shaped noise). In Experiment 1, children's memory span declined in the presence of two-talker speech but not in the presence of speech-shaped noise. This result was replicated in Experiment 2 after accounting for a potential effect of proactive interference due to repeated administration of the Missing Scan Task. Background speech, but not speech-shaped noise, disrupted working memory span in 5-year-old children. These results support the idea that background speech engages domain-general cognitive processes used during the recall of known objects in a way that speech-shaped noise does not.

Evaluating the Effects of Metalinguistic and Working Memory Training on Reading Fluency in Chinese and English: A Randomized Controlled Trial.

Children traditionally learn to read Chinese characters by rote, and thus stretching children’s memory span could possibly improve their reading in Chinese. Nevertheless, 85% of Chinese characters are semantic-phonetic compounds that contain probabilistic information about meaning and pronunciation. Hence, enhancing children’s metalinguistic skills might also facilitate reading in Chinese. In the present study, we tested whether training children’s metalinguistic skills or training their working-memory capacity in 8 weeks would produce reading gains, and whether these gains would be similar in Chinese and English. We recruited 35 second graders in Hong Kong and randomly assigned them to a metalinguistic training group (N = 13), a working-memory training group (10), or a waitlist control group (12). In the metalinguistic training, children were taught to analyze novel Chinese characters into phonetic and semantic radicals and novel English words into onsets and rimes. In the working-memory training, children were trained to recall increasingly long strings of Cantonese or English syllables in correct or reverse order. All children were tested on phonological skills, verbal working memory, and word reading fluency in Chinese and in English before and after training. Analyses of the pre- and post-test data revealed that only the metalinguistic training group, but not the other two groups, showed significant improvement on phonological skills in Chinese and English. Working-memory span in Chinese and English increased from the pre- to post-test in the working-memory training group relative to other two groups. Despite these domain-specific training effects, the two training groups improved similarly in word reading fluency in Chinese and English compared to the control group. Our findings suggest that increased metalinguistic skills and a larger working-memory span appear equally beneficial to reading fluency, and that these effects are similar in Chinese and English.

Executive functions and the contribution of short-term memory span in children with specific language impairment.

An increasing number of results show that specific language impairment (SLI) is often associated with impairments in executive functions (EF), but the nature, extent, and generality of these deficits is yet unclear. The aim of the paper is to present results from verbal and nonverbal tasks examining EF in children with SLI and their age-matched typically developing (TD) peers. 31 children with SLI were tested on verbal and nonverbal versions of simple and complex span, fluency, N-back, and Stroop tasks. Their performance was compared with 31 TD children matched on age and nonverbal IQ. The design allows us to examine whether executive functions are similarly affected in SLI in verbal and nonverbal tasks. The SLI group showed difficulties in verbal versions of complex span (listening span task) and fluency but not in inhibition (Stroop tasks) relative to TD age-matched children. Including simple verbal span (digit span) as a covariate eliminated group differences on both verbal tasks. Children with SLI were found to be impaired on several verbal measures of EF, but these differences were largely due to more fundamental deficits in verbal short-term span.

Speaking, writing, and memory span in children: Output modality affects cognitive performance

Low‐level processes of children's written language production are cognitively more costly than those involved in speaking. This has been shown by French authors who compared oral and written memory span performance. The observed difficulties of children's, but not of adults' low‐level processes in writing may stem from graphomotoric as well as from orthographic inadequacies. We report on five experiments designed to replicate and expand the original results. First, the French results were successfully replicated for German third‐graders, and for university students. Then, the developmental changes of the cognitive costs of writing were examined during primary school, comparing the performance of second‐ and fourth‐graders. Next, we show that unpractised writing modes, which were experimentally induced, also lead to a decrease of memory performance in adults, which supports the assumption that a lack of graphomotoric automation is responsible for the observed effects in children. However, unpractised handwriting yields clearer results than unpractised typing. Lastly, we try to separate the influences of graphomotoric as opposed to orthographic difficulties by having the words composed through pointing on a “spelling board”. This attempt, however, has not been successful, probably because the pointing to letters introduced other low‐level costs. In sum, throughout the four years of primary school, German children show worse memory span performance in writing compared to oral recall, with an overall increase in both modalities. Thus, writing had not fully caught up with speaking regarding the implied cognitive costs by the end of primary school. Therefore, conclusions relate to the question of how to assess properly any kind of knowledge and abilities through language production.

Verbal short‐term memory span in children: long‐term modality dependent effects of intrauterine growth restriction

Recent reports showed that children born with intrauterine growth restriction (IUGR) are at greater risk of experiencing verbal short-term memory span (STM) deficits that may impede their learning capacities at school. It is still unknown whether these deficits are modality dependent. This long-term, prospective design study examined modality-dependent verbal STM functions in children who were diagnosed at birth with IUGR (n = 138) and a control group (n = 64). Their STM skills were evaluated individually at 9 years of age with four conditions of the Visual-Aural Digit Span Test (VADS; Koppitz, 1981): auditory-oral, auditory-written, visuospatial-oral and visuospatial-written. Cognitive competence was evaluated with the short form of the Wechsler Intelligence Scales for Children--revised (WISC-R95; Wechsler, 1998). We found IUGR-related specific auditory-oral STM deficits (p < .036) in conjunction with two double dissociations: an auditory-visuospatial (p < .014) and an input-output processing distinction (p < .014). Cognitive competence had a significant effect on all four conditions; however, the effect of IUGR on the auditory-oral condition was not overridden by the effect of intelligence quotient (IQ). Intrauterine growth restriction affects global competence and inter-modality processing, as well as distinct auditory input processing related to verbal STM functions. The findings support a long-term relationship between prenatal aberrant head growth and auditory verbal STM deficits by the end of the first decade of life. Empirical, clinical and educational implications are presented.

Improving memory span in children with Down syndrome

Down syndrome (DS) is characterized by impaired memory span, particularly auditory verbal memory span. Memory span is linked developmentally to several language capabilities, and may be a basic capacity that enables language learning. If children with DS had better memory span, they might benefit more from language intervention. The present study evaluates a home-based parent-implemented intervention designed to improve auditory memory span in children with DS. Sixteen children with DS, age 6-14, completed one or two 3-month periods of memory training using overt cumulative rehearsal and auditory-only procedures. Children were divided into two groups. Group 1 completed 3 months of memory training followed by 3 months of visual activities, followed by three more months of memory training. Group 2 had the opposite schedule. Before and after each 3-month period, children came into the laboratory for memory assessment. Children improved in training sessions and a small amount on digit span, the primary proximal outcome assessment measure. Digit span improvement was linked to the memory training, as indicated by control comparisons and correlations. Improvement was correlated with language comprehension and verbal working memory, but not with non-verbal ability, age or home/behavioural variables. No improvement was evident on distal outcome measures (sentence memory and verbal working memory); however, a phonological similarity effect emerged coincidence with memory training, suggesting increased use of phonological codes in memory. Results suggest that some children with DS can improve their auditory verbal memory span with home-based rehearsal training, at least in limited ways. Children with good language and verbal working memory skills may be the best candidates for this type of training, even though they may show only small improvements. Still, small improvements in a severely impaired function are noteworthy, and justify further investigation.

The phonological similarity effect on memory span in children: Does it depend on age, speech rate, and articulatory suppression?

The present paper addresses issues surrounding the role of rehearsal and developmental increases in rehearsal speed regarding the phonological similarity effect (PSE) on immediate serial recall performance. In two experiments, school-aged children had to recall serially phonological similar and dissimilar words with or without concurrent articulation. Speech rate of the word material was also assessed. The size of the PSE was found to be independent of both age and speech rate. Furthermore, the size of the PSE was lower under articulatory suppression as compared to a standard condition without suppression. These results are consistent with the view that the PSE emerges because confusion during redintegration of degrading short-term codes is more likely for phonological similar items than for phonological distinct items. The occurrence of the PSE seems to be independent of rehearsal although articulatory suppression can moderate the size of the PSE. The parts of the redintegration mechanism that are responsible for the PSE seem to be age-invariant between 7 and 13 years.

The Association between Auditory Memory Span and Speech Rate in Children from Kindergarten to Sixth Grade

This study reexamined the association between speech rate and memory span in children from kindergarten to sixth grade (N = 152) in order to potentially account for the inconsistencies within the published literature on this topic. Some of the inconsistencies in past research may reflect the different methods adopted in assessing speech rate. In particular, repeating word triples may itself involve memory demands, contaminating the correlation between speech rate and memory span in younger children. Analyses using composite speech rate and memory span measures showed that speech rate for word triples shared variance with memory span that was independent of speech rate for single words. Moreover, speech rate for word triples was largely redundant with age in explaining additional variation in memory span once the effects of speech rate for single words were controlled.

What limits children's working memory span? Theoretical accounts and applications for scholastic development.

Explanations of working memory span in children were studied in a longitudinal follow-up of J. N. Towse, G. J. Hitch, and U. Hutton (1998). Reading span and operation span were lower when within-task retention intervals were lengthened. For each task, variation in span between test waves and age cohorts was systematically related to changes in processing speed. The two spans explained substantial shared variance in both reading and arithmetic scores, with some evidence for domain specificity. Combined span scores predicted unique variance in scholastic attainment over a 1-year interval. The authors concluded that working memory span is constrained by rapid loss of active codes and is not simply a measure of capacity for resource sharing. Working memory is also implicated in scholastic development.

What limits children's working memory span? Theoretical accounts and applications for scholastic development.

Explanations of working memory span in children were studied in a longitudinal follow-up of J. N. Towse, G. J. Hitch, and U. Hutton (1998). Reading span and operation span were lower when within-task retention intervals were lengthened. For each task, variation in span between test waves and age cohorts was systematically related to changes in processing speed. The two spans explained substantial shared variance in both reading and arithmetic scores, with some evidence for domain specificity. Combined span scores predicted unique variance in scholastic attainment over a 1-year interval. The authors concluded that working memory span is constrained by rapid loss of active codes and is not simply a measure of capacity for resource sharing. Working memory is also implicated in scholastic development.

Verbal Memory Span in Children: Speech Timing Clues to the Mechanisms Underlying Age and Word Length Effects

According to the prevalent articulatory loop hypothesis of memory span (Baddeley, 1986), subjects recall items from a decaying phonological store that is refreshed by a covert articulatory process. The rate of covert articulation is said to determine memory span. The present research indicates that this account underemphasizes effects of (1) other covert mnemonic processes and (2) overt pronunciation in recall. Memory span and maximal speech rate for sets of one-, two-, and three-syllable words were examined in groups of children with mean ages of 4;5 and 8;8. Although the usual linear relation between the maximal speech rate and memory span was replicated, speech timing measurements based on the memory responses revealed that age and word length effects had different effects on the timing of responding. Whereas word length affected the duration of words in the response but not silent intervals, age affected the duration of silent, preparatory and interword intervals in the response but not the duration of words. These results are discussed in light of the hypothesis that the speeds of multiple, mnemonically relevant covert and overt processes affect memory span.

The Relationship between Speech Rate and Memory Span in Children

Evidence of a linear relationship between speech rate and memory span in children has been obtained in several studies (e.g. Hulme, Thomson, Muir, &amp; Lawrence, 1984). This evidence is used to support an explanation of the development of memory span based on the working memory model (Baddeley, 1990). The model argues that speech rate is related to the amount recalled and that developmental increases in speech rate allow faster rehearsal with age and, hence, greater recall. However, the linear relationship between speech rate and memory span has generally been reported in terms of group means for speech rate and memory span rather than individual level correlations between the two variables. The present studies replicate the group relationship, but find that correlations between individual subject's speech rates and memory spans, when the effects of age are partialled out, are no longer significant. Nor was the size of the word length effect related to the difference in speech rate between short and long words. It is argued that the group mean relationship between speech rate and memory span is clear and replicable, but that the speech rates of individual children are not good predictors of those children's memory spans. The implications of these results for the working memory explanation of span development are discussed.

Learning disabled and nondisabled children's performance on serial recall tasks: The facilitating effect of knowledge

Learning disabled (LD) and nondisabled (NonLD) children's memory span was assessed using lists of items that varied both in length and familiarity (digits, unfamiliar faces, familiar faces). Fifty boys in grades four through six, half of whom were identified as learning disabled, participated in the experiment. Both the LD and NonLD children recalled more items in the digit and familiar faces conditions than in the unfamiliar faces condition, demonstrating the importance of knowledge base in children's serial recall. of greater importance, however, was the difference between the LD and NonLD children for the three types of stimuli. NonLD children showed a recall advantage compared to their LD peers for digits and unfamiliar faces, but not for familiar faces. The results are interpreted as demonstrating the facilitating effect of knowledge on memory, particularly for learning impaired children.

Enhancement of 4-year-old children's memory span for phonologically similar and dissimilar word lists

Previous research suggests that preschool children are deficient in rehearsal and that stimulus list repetitions can improve their recall, presumably by substituting for the products of rehearsal. However, the previous research included interitem or postlist retention intervals of several seconds or more. We examined the utility of list repetitions with reference to an ordinary span task in which spoken words were presented 1 s apart for immediate recall. Lists with phonologically similar versus dissimilar items were included, to determine if the overall pattern of recall could be made more similar to what is ordinarily obtained in older children. Cumulative repetition was found to cause a moderate increase in both memory span and the phonological similarity effect. Other types of list repetition provided more insight into types of stimulus redundancy that were helpful (e.g., repeated serial order information) or not helpful (e.g., forced articulatory coding) to children attempting to recall spoken lists. The underlying mnemonic processes are discussed.

Item Identification Time and Rehearsal Rate as Predictors of Memory Span in Children

According to the working memory model of Baddeley and Hitch (1974), the sensitivity of memory span to word length arises from the time taken to rehearse items in a speech-based “articulatory loop”. Alternatively, it has been suggested that the word-length effect may result from differences in the speed of perceptual processes of item identification. Changes in the speed of rehearsal and of item identification have also been claimed to contribute to the growth of memory span that is seen in development. In order to compare these two variables directly, groups of children aged 8 and 11 were assessed on memory span for words of one, two, and three syllables; span under articulatory suppression; rehearsal rate; and item identification time. Span was found to be a linear function of rehearsal rate across differences in both word length and age. The word-length effect was unrelated to item identification time and was diminished by articulatory suppression. These results show that the word-length effect reflects rehearsal and not item identification processes. However, the results also suggest that changes in item identification time contribute to developmental differences in span when articulation is suppressed. A distinction between item identification and rehearsal effects can be readily interpreted in terms of the working memory model if it is assumed that they indicate the efficiency of different subsystems involved in span.

Working memory in children

It is frequently assumed that the development of children’s abilities in short-term memory reflects changes in a unitary short-term store. This approach makes only poor contact with recent research on adults, which suggests the idea of a more complex ‘ working memory ’ system consisting of a limited-capacity central processor controlling a number of special-purpose stores. Two such stores are (i) the articulatory loop, a subsystem involved in subvocal rehearsal and associated with memory span, and (ii) the visuo-spatial scratch-pad, involved in imagery. This paper considers the applicability of the working memory framework to the study of children’s memory. In adults, memory span for words is affected by their length, varying linearly with the rate at which they can be articulated, and thus presumably rehearsed. Studies of the developmental growth of memory span in children show that the same linear relation describes performance, with older children’s better memory associated with faster rates of articulation. It appears from this that developmental change corresponds to an increase in the efficiency of subvocal rehearsal, with the decay characteristic of the articulatory loop remaining constant. However, although this simple developmental pattern is observed in memory for sequences of spoken words it is not present when the items are nameable pictures. Further investigation shows that older children use the articulatory loop to remember picture names: their performance is sensitive to phonemic similarity of the names and articulatory interference. However, younger children’s performance is not affected by either of these factors but is sensitive to visual similarity. It is suggested that such children may be storing material in the visuo-spatial scratch-pad. An additional aspect of working memory is that separate mechanisms are thought to be involved in memory span and the ‘recency effect’, the tendency for recent items in a list to be remembered well in unordered recall. A review of evidence obtained with children suggests that age differences in these two phenomena are independent. In general, therefore, it seems difficult to interpret the developmental changes reported here in terms of a unitary short-term store, and it is concluded that working memory provides a more promising approach.

THE EFFECT OF NONVERBAL CUES ON THE RETENTION OF KINDERGARTEN CHILDREN

4 methods of giving instructions (concerning manipulations of familiar obfects) were compared in terms of their effect on the nonverbal retention of 52 middle-class kindergarten Ss. Each of the conditions was presented to separate groups of Ss-13 per group. When nonverbal cues were presented simultaneously with a verbal instruction, retention was significantly greater than with the verbal instruction alone. The results are discussed in terms of the representational requirements for retention under the four conditions of presentation. Reviews of the literature on the memory span of children (Munn, 1954; Van De Moortel, 1965) have generally concluded that the memory span of preschool children is relatively limited but increases gradually with age. The direct conclusion from typical memory-span studies has led to the general assumption that memory capacity undergoes a relatively systematic change in terms of the quantity of material which can be retained. However, consideration of the representational requirements of typical memory span procedures in relation to developmental changes in the nature of the child's representational system suggests