Manipulating articulatory demands in non-word repetition: a 'late-8' non-word repetition task

Attentional Refreshing in the Absence of Long-Term Memory Content: Role of Short-Term and Long-Term Consolidation

Contradictory results in the literature suggest that attentional refreshing can seemingly not operate efficiently in the absence of semantic representations, while at the same time it does not rely directly on retrieval from semantic memory. The objective of the present study was a better understanding of the bidirectional links between working memory (WM) and long-term memory (LTM), by assessing on the one hand the role of WM mechanisms in long-term recall and on the other hand how their functioning is modulated by the prior LTM content. Through two experiments, we investigated a new hypothesis: attentional refreshing requires stable WM representations independently of the presence or the absence of associated LTM traces. We manipulated this stability through short-term consolidation (Experiment 1) and multiple presentations of memoranda (Experiment 2) to evaluate how it would affect maintenance of words and pseudowords. While we found that lexicality, short-term consolidation and multiple presentations affected short-term and long-term recall, both experiments converged on the conclusion that none of these factors modulated the effect of the cognitive load of the concurrent processing task, suggesting that refreshing does not depend on LTM content nor WM representations' stability. Additionally, we found that delayed recall performance was not affected by the cognitive load, in contradiction with previous literature. These results provide new insight into the functioning of refreshing and the links between WM and LTM.

Consonant Age of Acquisition Reveals Nonlinear Effects in Nonword Repetition Performance

Recent work has shown significant sublexical effects of long-term memory in nonword repetition (NWR) using a dichotomous consonant age of acquisition (CAoA) variable (Moore, 2018; Moore, Fiez, and Tompkins, 2017). Performance consistently decreased when stimuli comprised consonants acquired later versus earlier in speech development. To address potential confounds related to stimulus design and linearity, the purpose of this study was to test whether performance decreases as the CAoA value of stimuli increases in various linguistic tasks using a continuous CAoA variable. Thirty-one college students completed NWR and other linguistic tasks in which the stimuli varied in average CAoA values. Data were analyzed using multilevel modeling. After accounting for phonotactic probability, CAoA was a statistically significant predictor of performance across the models reported. The relationship was more complex in some of the models in which CAoA showed a statistically significant nonlinear relationship with the outcome measure. Results from this study support previous work showing that CAoA affects performance on NWR and other linguistic tasks that vary in their memory, auditory perceptual, and articulatory demands. Importantly, this line of work was extended here by demonstrating that the CAoA effect is robust across novel stimulus sets and study designs, and may be more complex than previously understood when using a dichotomous CAoA variable. Quadratic results suggest that the CAoA variable has a differential effect on performance for low to moderate CAoA values, but for higher CAoA values the effect is similarly negative. The nonlinear relationship between CAoA and measures of speed and accuracy on some of the tasks warrants further study into the complex relationship between various predictive factors that contribute to language performance.

Spectral degradation influences phonological memory in typically hearing adults

Phonological processing is a fundamental component of language, can be impaired in people with hearing loss, and involves several confounded subprocesses. The purpose of this study was to systematically examine several phonological subprocesses - i.e., the spectral quality of auditory input and phonological short-term and long-term memory - in order to better understand how they interact with one another in basic linguistic tasks. Using an experimental, within-subjects design, 30 typically-hearing adults completed nonword repetition (NWR) and auditory lexical decision (ALD) tasks varying in spectral quality (normal versus spectrally-degraded), consonant age of acquisition (CAoA; i.e. early-acquired versus late-acquired consonants), syllable length (NWR task), and lexical status (ALD task). In NWR, spectral degradation muted the word length effect, though performance differed depending on how familiar participants were with the degraded stimuli. ALD findings showed that the magnitude of the degradation effect varied between stimuli comprising early-acquired versus late-acquired consonants. The robust effect of spectral degradation on phonological short-term and long-term memory provides a model of the interactive nature of these subprocesses in typical adults. Future work with populations with hearing loss can provide a comparison to help understand how the typical and clinical phonological systems differ.

The Challenge of Rich Vocabulary Instruction for Children With Developmental Language Disorder

Purpose The aims of the study were to explore responses of children with developmental language disorder (DLD) to rich vocabulary instruction and to identify potential factors that contribute to outcomes. Method Children with DLD participated in a language intervention embedded within a science camp. Using parent and clinician reports, standardized tests, probes, notes, and video, we derived descriptions of seven of the campers who received a vocabulary intervention that incorporated principles of rich instruction. We present them here as a case series. Results Five cases responded to the intervention with modest gains in Tier 2 science vocabulary and science knowledge. One case demonstrated no response, and another was unable to complete the intervention. The latter two cases presented with triple risks: DLD, executive function deficits, and stressors associated with poverty. In comparison, the best responder also lived in poverty and had DLD, but he had intact executive function, strengths in extant vocabulary, stronger knowledge of science, better engagement in the science and language intervention activities, and was older. Other factors that seemed to contribute to outcomes included the complexity of the word forms and dosage. Conclusions Translating research on rich instruction to clinical practice is challenging. This case series motivated hypotheses about the nature of the challenge and what to do about it, the primary one being that the modest success of rich vocabulary instruction for children with DLD is not a limitation of the approach itself but rather a reflection of the difficulty of delivering the intervention while tailoring the targets, approach, and dosage to the needs of individual children with DLD. Supplemental Material https://doi.org/10.23641/asha.13667699.

A comparison of the performance of Persian speaking children who do and do not stutter on three nonwords repetition tasks

PURPOSE

The purpose of the study was to examine the performance of Persian speaking children who stutter (CWS) and children who do not stutter (CWNS) on three nonword repetition tasks, while also focusing on which task and scoring method best differentiates the two groups of children.

METHOD

Thirty CWS and 30 CWNS between the ages of 5;0 to 6;6 completed three nonword repetition tasks that varied in complexity. Each task was scored using two methods: nonwords correct and phonemes correct. Between-group differences in performance on each task were examined, along with disfluencies for CWS and the task and scoring method that best differentiated the CWS and CWNS.

RESULTS

The findings revealed that, across all three nonword repetition tasks, the CWS consistently produced fewer nonwords correct and phonemes correct than the CWNS group at virtually all syllable lengths. The CWS produced more disfluencies on longer nonwords than shorter nonwords in all three nonword repetition tasks. The nonword repetition task with lower wordlikeness and more phonologically complex items best differentiated the two groups of children. Findings further revealed that discriminative accuracy was highest for scoring based on the number of phonemes produced correctly.

CONCLUSION

Findings provide further evidence to suggest that CWS may have difficulty with phonological working memory and/or phonological processing.

Perceptual Learning and Production Practice Differentially Affect How Children Produce Novel Words

Purpose Perceptual learning and production practice are basic mechanisms that children depend on to acquire adult levels of speech accuracy. In this study, we examined perceptual learning and production practice as they contributed to changes in speech accuracy in 3- and 4-year-old children. Our primary focus was manipulating the order of perceptual learning and production practice to better understand when and how these learning mechanisms interact. Method Sixty-five typically developing children between the ages of 3 and 4 years were included in the study. Children were asked to produce CVCCVC (C = consonant, V = vowel) nonwords like /bozjəm/ and /tʌvtʃəp/ that were described as the names of make-believe animals. All children completed two separate experimental blocks: a control block in which participants heard each nonword once and repeated it, and a test block in which the perceptual input frequency of each nonword varied between 1 and 10. Half of the participants completed a control-test order; half completed a test-control order. Results Greater accuracy was observed for nonwords produced in the second experimental block, reflecting a production practice effect. Perceptual learning resulted in greater accuracy during the test for nonwords that participants heard 3 times or more. However, perceptual learning did not carry over to control productions in the test-control design, suggesting that it reflects a kind of temporary priming. Finally, a post hoc analysis suggested that the size of the production practice effect depended on the age of acquisition of the consonants that comprised the nonwords. Conclusions The study provides new details about how perceptual learning and production practice interact with each other and with phonological aspects of the nonwords, resulting in complex effects on speech accuracy and learning of form-referent pairs. These findings may ultimately help speech-language pathologists maximize their clients' improvement in therapy. Supplemental Material https://doi.org/10.23641/asha.12971411.

Consonant Age-of-Acquisition Effects in Nonword Repetition Are Not Articulatory in Nature

PURPOSE

Most research examining long-term-memory effects on nonword repetition (NWR) has focused on lexical-level variables. Phoneme-level variables have received little attention, although there are reasons to expect significant sublexical effects in NWR. To further understand the underlying processes of NWR, this study examined effects of sublexical long-term phonological knowledge by testing whether performance differs when the stimuli comprise consonants acquired later versus earlier in speech development.

METHOD

Thirty (Experiment 1) and 20 (Experiment 2) college students completed tasks that investigated whether an experimental phoneme-level variable (consonant age of acquisition) similarly affects NWR and lexical-access tasks designed to vary in articulatory, auditory-perceptual, and phonological short-term-memory demands. The lexical-access tasks were performed in silence or with concurrent articulation to explore whether consonant age-of-acquisition effects arise before or after articulatory planning.

RESULTS

NWR accuracy decreased on items comprising later- versus earlier-acquired phonemes. Similar consonant age-of-acquisition effects were observed in accuracy measures of nonword reading and lexical decision performed in silence or with concurrent articulation.

CONCLUSION

Results indicate that NWR performance is sensitive to phoneme-level phonological knowledge in long-term memory. NWR, accordingly, should not be regarded as a diagnostic tool for pure impairment of phonological short-term memory.

SUPPLEMENTAL MATERIALS

https://doi.org/10.23641/asha.5435137.

Multipoint genome-wide linkage scan for nonword repetition in a multigenerational family further supports chromosome 13q as a locus for verbal trait disorders

Verbal trait disorders encompass a wide range of conditions and are marked by deficits in five domains that impair a person's ability to communicate: speech, language, reading, spelling, and writing. Nonword repetition is a robust endophenotype for verbal trait disorders that is sensitive to cognitive processes critical to verbal development, including auditory processing, phonological working memory, and motor planning and programming. In the present study, we present a six-generation extended pedigree with a history of verbal trait disorders. Using genome-wide multipoint variance component linkage analysis of nonword repetition, we identified a region spanning chromosome 13q14-q21 with LOD = 4.45 between 52 and 55 cM, spanning approximately 5.5 Mb on chromosome 13. This region overlaps with SLI3, a locus implicated in reading disability in families with a history of specific language impairment. Our study of a large multigenerational family with verbal trait disorders further implicates the SLI3 region in verbal trait disorders. Future studies will further refine the specific causal genetic factors in this locus on chromosome 13q that contribute to language traits.

Phonological memory in young children who stutter

This study investigated phonological memory in 5- and 6-year old children who stutter. Participants were 11 children who stutter matched on general language abilities, maternal education level, and sex to 11 typically fluent children. Participants completed norm-referenced nonword repetition and digit span tasks, as well as measures of expressive and receptive vocabulary and articulation. The nonword repetition task included stimuli that ranged from 1 to 7 syllables, while the digit naming task contained number strings containing 2-10 digits. Standardized tests of vocabulary and articulation abilities were tested as well. Groups were comparable on measures expressive vocabulary, receptive vocabulary, and articulation. Despite the fact that the majority of participants scored within typical limits, young children who stutter still performed significantly less well than children who do not stutter on the nonword repetition task. No between-group differences were revealed in the digit naming task. Typically fluent children demonstrated strong correlations between phonological memory tasks and language measures, while children who stutter did not. These findings indicate that young children who stutter may have sub-clinical differences in nonword repetition.

Serial-position effects on a free-recall task in bilinguals

In this study, we examined mechanisms that underlie free-recall performance in bilinguals' first language (L1) and second language (L2) through the prism of serial-position effects. On free-recall tasks, a typical pattern of performance follows a U-shaped serial-position curve, where items from the beginning of the list (the primacy effect) and items from the end of the list (the recency effect) are recalled with higher accuracy than items from the middle of the list. The present study contrasted serial-position effects on the free-recall task in Korean-English bilinguals' L1 vs. L2 and examined the relationship between an independent working memory (WM) measure and serial-position effects in bilinguals' two languages. Results revealed stronger pre-recency (primacy and middle) effects in L1 than in L2, but similar recency effects in the two languages. A close association was observed between WM and recall performance in the pre-recency region in the L1 but not in the L2. Together, these findings suggest that linguistic knowledge constrains free-recall performance in bilinguals, but only in the pre-recency region.

Phonological encoding of young children who stutter

PURPOSE

Several empirical studies suggest that children who stutter, when compared to typically fluent peers, demonstrate relatively subtle, yet robust differences in phonological encoding. Phonological encoding can be measured through the use of tasks that reflect the underlying mechanisms of phonological processing, such as phonological awareness. This study investigated the phonological encoding abilities of five- and six-year old children who stutter.

METHODS

Young children who stutter were paired according to language ability, maternal education, and sex to their typically fluent peers. Participants completed multiple measures of phonological awareness abilities (i.e., sound matching, phoneme blending, elision), as well as measures of expressive and receptive vocabulary and articulation.

RESULTS

Young children who stutter performed significantly less well than nonstuttering peers on tasks of elision and sound blending. No between-group differences were found in sound matching abilities or in any of the background language measures.

CONCLUSIONS

Results suggest that young children who stutter have subtle, yet robust, linguistic differences in certain aspects of phonological encoding that may contribute to an unstable language planning system in young children who stutter.

EDUCATIONAL OBJECTIVES

The reader will be able to: (a) describe how phonological awareness can inform our understanding of phonological encoding; (b) summarize the findings of previously published studies that examined some aspects of phonological awareness in children who do and do not stutter; and (c) compare the results of the current study with other investigations of phonological awareness skills in children who stutter and their typically fluent peers.