Relationship between language and fluency in children with developmental language disorders

Rates of Typical Disfluency in the Conversational Speech of 30-Month-Old Spanish-English Simultaneous Bilinguals

PURPOSE

The aim of this study was to investigate the typical disfluency rates at 30 months old in a large group of simultaneous bilingual children and also investigate the relationships between disfluency rates and linguistic complexity (mean length of utterance in words [MLU-W]), vocabulary diversity (VocD), and speaking rate (utterances per unit time).

METHOD

Fifty-three typically developing children who had been exposed to Spanish and English from birth participated in this descriptive study. The average percent input at home was 46% in English and 54% in Spanish. Outside the home, the children averaged 9 hr of exposure per week in each language. Spontaneous speech samples in both languages were obtained during play sessions between the children and a parent.

RESULTS

Nonparametric tests revealed a significant difference in typical disfluency rates across languages, with more children being disfluent in English and with a larger range of disfluency rates in English. The effect size for this difference was small. The children had significantly higher MLU-W in English; there were no differences in VocD or speaking rate between the 2 languages. Typical disfluency rate in Spanish was not significantly correlated with MLU-W, VocD, or speaking rate. Typical disfluency rates in English were correlated with MLU-W and VocD, but not with speaking rate.

CONCLUSION

This article described the typical disfluency rates of a large group of simultaneous Spanish-English bilingual children at 30 months of age. The typical disfluency rates reported here are lower than those reported in the literature for monolingual children of similar ages. Clinical implications of these findings are addressed.

Neural Indices of Semantic Processing in Early Childhood Distinguish Eventual Stuttering Persistence and Recovery

Purpose

Maturation of neural processes for language may lag in some children who stutter (CWS), and event-related potentials (ERPs) distinguish CWS who have recovered from those who have persisted. The current study explores whether ERPs indexing semantic processing may distinguish children who will eventually persist in stuttering (CWS-ePersisted) from those who will recover from stuttering (CWS-eRecovered).

Method

Fifty-six 5-year-old children with normal receptive language listened to naturally spoken sentences in a story context. ERP components elicited for semantic processing (N400, late positive component [LPC]) were compared for CWS-ePersisted, CWS-eRecovered, and children who do not stutter (CWNS).

Results

The N400 elicited by semantic violations had a more focal scalp distribution (left lateralized and less anterior) in the CWS-eRecovered compared with CWS-ePersisted. Although the LPC elicited in CWS-eRecovered and CWNS did not differ, the LPC elicited in the CWS-ePersisted was smaller in amplitude compared with that in CWNS.

Conclusions

ERPs elicited in 5-year-old CWS-eRecovered compared with CWS-ePersisted suggest that future recovery from stuttering may be associated with earlier maturation of semantic processes in the preschool years. Subtle differences in ERP indices offer a window into neural maturation processes for language and may help distinguish the course of stuttering development.

Speech-Language Dissociations, Distractibility, and Childhood Stuttering

PURPOSE

This study investigated the relation among speech-language dissociations, attentional distractibility, and childhood stuttering.

METHOD

Participants were 82 preschool-age children who stutter (CWS) and 120 who do not stutter (CWNS). Correlation-based statistics (Bates, Appelbaum, Salcedo, Saygin, & Pizzamiglio, 2003) identified dissociations across 5 norm-based speech-language subtests. The Behavioral Style Questionnaire Distractibility subscale measured attentional distractibility. Analyses addressed (a) between-groups differences in the number of children exhibiting speech-language dissociations; (b) between-groups distractibility differences; (c) the relation between distractibility and speech-language dissociations; and (d) whether interactions between distractibility and dissociations predicted the frequency of total, stuttered, and nonstuttered disfluencies.

RESULTS

More preschool-age CWS exhibited speech-language dissociations compared with CWNS, and more boys exhibited dissociations compared with girls. In addition, male CWS were less distractible than female CWS and female CWNS. For CWS, but not CWNS, less distractibility (i.e., greater attention) was associated with more speech-language dissociations. Last, interactions between distractibility and dissociations did not predict speech disfluencies in CWS or CWNS.

CONCLUSIONS

The present findings suggest that for preschool-age CWS, attentional processes are associated with speech-language dissociations. Future investigations are warranted to better understand the directionality of effect of this association (e.g., inefficient attentional processes → speech-language dissociations vs. inefficient attentional processes ← speech-language dissociations).

Neurodevelopment for syntactic processing distinguishes childhood stuttering recovery versus persistence

BACKGROUND

Characterized by the presence of involuntary speech disfluencies, developmental stuttering is a neurodevelopmental disorder of atypical speech-motor coordination. Although the etiology of stuttering is multifactorial, language development during early childhood may influence both the onset of the disorder and the likelihood of recovery. The purpose of this study was to determine whether differences in neural indices mediating language processing are associated with persistence or recovery in school-age children who stutter.

METHODS

Event-related brain potentials (ERPs) were obtained from 31 6-7-year-olds, including nine children who do not stutter (CWNS), 11 children who had recovered from stuttering (CWS-Rec), and 11 children who persisted in stuttering (CWS-Per), matched for age, and all with similar socioeconomic status, nonverbal intelligence, and language ability. We examined ERPs elicited by semantic and syntactic (phrase structure) violations within an auditory narrative consisting of English and Jabberwocky sentences. In Jabberwocky sentences, content words were replaced with pseudowords to limit semantic context. A mixed effects repeated measures analysis of variance (ANOVA) was computed for ERP components with four within-subject factors, including condition, hemisphere, anterior/posterior distribution, and laterality.

RESULTS

During the comprehension of English sentences, ERP activity mediating semantic and syntactic (phrase structure) processing did not distinguish CWS-Per, CWS-Rec, and CWNS. Semantic violations elicited a qualitatively similar N400 component across groups. Phrase structure violations within English sentences also elicited a similar P600 component in all groups. However, identical phrase structure violations within Jabberwocky sentences elicited a P600 in CWNS and CWS-Rec, but an N400-like effect in CWS-Per.

CONCLUSIONS

The distinguishing neural patterns mediating syntactic, but not semantic, processing provide evidence that specific brain functions for some aspects of language processing may be associated with stuttering persistence. Unlike CWS-Rec and CWNS, the lack of semantic context in Jabberwocky sentences seemed to affect the syntactic processing strategies of CWS-Per, resulting in the elicitation of semantically based N400-like activity during syntactic (phrase structure) violations. This vulnerability suggests neural mechanisms associated with the processing of syntactic structure may be less mature in 6-7-year-old children whose stuttering persisted compared to their fluent or recovered peers.

Speech disfluencies of preschool-age children who do and do not stutter

PURPOSE

The goals of the present study were to investigate whether (1) the speech disfluencies of preschool-age children are normally distributed; (2) preschool-age children who do (CWS) and do not stutter (CWNS) differ in terms of non-stuttered disfluencies; (3) age, gender, and speech-language ability affect the number and type of disfluencies children produce; and (4) parents' expressed concern that their child stutters is associated with examiners' judgments of stuttered disfluency.

METHOD

Four hundred and seventy two children participated, of which 228 were CWS (56 girls), and 244 CWNS (119 girls). Participants provided conversational speech samples that were analyzed for frequency of occurrence of (a) stuttered disfluencies, (b) non-stuttered disfluencies, and (c) total disfluencies.

RESULTS

Results indicated that the underlying distributions of preschool-age children's stuttered and non-stuttered disfluency counts followed a negative binomial distribution (i.e., were not normal), with more children "piling up" at the low end [none or few disfluencies] and fewer children scoring in the upper [more severe stuttering] end of the distribution. Findings also indicated that non-stuttered disfluencies significantly predicted CWS/CWNS talker group classification, information that may be helpful to augment, but not supplant, talker group classification criteria based on stuttered disfluencies. Moreover, expressed parental concern about stuttering was strongly associated with frequency of stuttered disfluencies.

CONCLUSION

Findings suggest that the entirety of preschool-age CWS' speech disfluencies - non-stuttered as well as stuttered - differs from that of their CWNS peers and that because these disfluencies are not normally distributed statistical analyses assuming normality of distribution are not the most appropriate means to assess these differences. In addition, certain "third-order" variables (e.g., gender) appear to impact frequency of children's disfluencies and expressed parental concerns about stuttering are meaningfully related to examiners' judgments of stuttered disfluencies.

LEARNING OUTCOMES

The reader will recognize differences in speech disfluencies of preschool-age children who do and do not stutter. The reader will recognize whether age, gender and speech-language ability affect the number and type of disfluencies children produce. The reader will describe whether parental concern about stuttering is associated with examiners' judgments of stuttering.

Preliminary study of disfluency in school-aged children with autism

BACKGROUND

In recent years, there has been increased identification of disfluencies in individuals with autism, but limited examination of disfluencies in the school-age range of this population. We currently lack information about whether the disfluencies of children with autism represent concomitant stuttering, normal disfluency, excessive normal disfluency, or some form of disfluency unique to the school-age population of children with autism.

AIMS

This paper explores the nature of disfluencies in school-aged children with autism in comparison with matched children who stutter and controls. It explores stuttering-like disfluencies, non-stuttering-like disfluencies and word-final disfluencies.

METHODS & PROCEDURES

This study compared disfluency patterns in 11 school-aged children with Asperger's syndrome (AS), 11 matched children who stutter (CWS), and 11 matched children with no diagnosis (ND). Analyses were based on speech samples collected during an expository discourse task.

OUTCOMES & RESULTS

Results reveal statistically significant differences between children with AS and CWS and between children with AS and those with ND for the percentage of words containing stuttering-like disfluencies. In the AS group, four out of 11 (36%) met the common diagnostic criteria for a fluency disorder. Disfluencies in the AS group differed qualitatively and quantitatively from the CWS, and included a larger distribution of word-final disfluencies.

CONCLUSIONS & IMPLICATIONS

This study provides initial data regarding patterns of disfluency in school-aged children with AS that, with careful consideration and the cautious application of all findings, can assist therapists in making more evidence-based diagnostic decisions. Findings offer evidence that when working with children with AS, disfluencies both similar and dissimilar to those of CWS may be identified in at least a subset of those with AS. Therefore, children with AS should be screened for fluency disorders during their initial evaluation and treated if it is determined that the fluency disorder negatively impacts the effectiveness of communication.

Fluency patterns in narratives from children with localization related epilepsy

This study assessed the relationship between fluency and language demand in children with epilepsy, a group known to demonstrate depressed language skills. Disfluency type and frequencies were analyzed in elicited narratives from 52 children. Half of these children had localization-related epilepsy (CWE), while the others were age- and gender-matched typically-developing (TD) peers. CWE were found to be significantly more disfluent overall than their matched TD peers during narrative productions, and demonstrated a higher proportion of stutter-like disfluencies, particularly prolongations. The current study adds to an emerging literature that has found depressed language skills and listener perceptions of verbal ability in children with chronic seizure activity, and contributes to the small but growing literature that suggests that disfluency during spoken language tasks may be a subtle marker of expressive language impairment.

EDUCATIONAL OBJECTIVES

The reader will be able to (a) describe why children with epilepsy might be at greater risk for language delays and or increased levels of disfluency; (b) describe profiles of fluency that differentiated children with chronic and recent-onset epilepsy from their age and gender matched peers; and (c) apply this information to monitoring of children with seizure disorder on their caseloads.

Speech timing and pausing in children with specific language impairment

Articulation rate, speaking rate, as well as the duration and location of pauses, were analysed in 10 children with specific language impairment (SLI) and a comparison group of seven younger children producing utterances of similar lengths. Children with SLI were significantly slower in articulation rate, but not speaking rate or pausing time, indicating a group difference attributable to longer syllable duration. The correlation between the duration of the pause preceding a child's speaking turn and the length of the subsequent child utterance was calculated as an indication of children's use of the pause for planning the utterance. The correlation was not significant in either group, and not significantly different between groups. An analysis of the position of pauses within speaking turns showed more syllables following than preceding the pause, with no significant group differences. Theoretical implications are discussed.

Childhood stuttering and dissociations across linguistic domains: a replication and extension

The purpose of this investigation was to replicate the methods of Anderson, Pellowski, and Conture (2005) to determine whether a different sample of preschool children who stutter (CWS) exhibit more dissociations in speech-language abilities than children who do not stutter (CWNS; Study 1) and to examine the relation between dissociations and specific characteristics of stuttering (e.g., most common disfluency type) using a much larger sample size (Study 2). Participants for Study 1 were 40 CWS and 40 CWNS between the ages of 3;0 and 5;11. Participants for Study 2 were the same as for Study 1 plus the 45 CWS and 45 CWNS used by Anderson et al. (2005) for a total of 85 CWS and 85 CWNS. Participants were administered five standardized speech-language (sub)tests and a conversational speech sample was obtained from each participant for the analyses of speech disfluencies/stuttering. Standard scores from the standardized speech-language tests were analyzed using a correlation-based statistical procedure (Bates, Applebaum, Sacedo, Saygin, & Pizzamiglio, 2003) to identify possible dissociations among the speech-language measures. Findings from Study 1 supported Anderson et al.'s findings that CWS exhibited significantly more speech-language dissociations than CWNS. Results from Study 2 further revealed that CWS who exhibited dissociations were more likely to exhibit non-stuttered (other) disfluencies as their most common disfluency type. Findings provide further support for the possibility that dissociations among various aspects of the speech-language system may contribute to the difficulties that some children have establishing normally fluent speech.

EDUCATIONAL OBJECTIVES

The reader will be able to: (a) summarize findings from previous studies examining the speech and language performance of children who do and do not stutter; (b) describe the concept of "dissociations" in the speech and language skills of young children; (c) compare the results of the present study with previous work in this area; and (d) discuss speculations concerning the manner in which dissociations might affect fluency development in children who stutter.

Analysis of oral narratives of children who stutter and their fluent peers: kindergarten through second grade

Measures of language sample length (in c-units) and morphological, syntactic, and narrative abilities were obtained from oral narrative transcripts of 22 children who stutter and 22 children who do not stutter; participants attended kindergarten, first, and second grades. A two-way MANOVA yielded significant main effects for grade, with significant differences on some measures evidenced between participants in kindergarten and second grades. No significant differences between groups or group-grade interaction effects on the measures were obtained. Grade-wise comparisons (through t-tests) indicated that the performance of children who stutter did not differ significantly from their typically fluent peers on all dependent measures; however, kindergarten children who stutter obtained the most discrepant (lower) scores than their grade-matched fluent peers on the Narrative Scoring Scheme measure, with group differences approaching statistical significance on this measure. The findings suggest that children who do and do not stutter evidence similar expressive language abilities, even as subgroups of children who stutter may lag behind their grade-matched fluent peers in particular language domains.

Lexical priming in picture naming of young children who do and do not stutter

The purpose of this investigation was to assess the influence of lexical/semantic priming on the speech reaction time of young children who do and do not stutter during a picture-naming task. Participants were 23 children who stutter, age-matched (+/-4 months) to 23 children who do not stutter, ranging in age from 3;0 (years;months) to 5;11. Procedures involved a computer-assisted picture-naming task, during which each participant was presented with the same set of 28 pictures in each of 3 different conditions: (a) no-prime condition, in which no auditory stimulus was presented before picture display; (b) related-prime condition, in which a word, semantically related to the target picture, was presented auditorily 700 ms before picture display; and (c) unrelated-prime condition, in which a semantically unrelated word was presented auditorily 700 ms before picture display. Results indicated that when compared with a no-prime condition, presentation of semantically related words before the picture-naming response led to shorter or faster speech reaction times for children who do not stutter, but for children who stutter, it led to longer or slower speech reaction times. Moreover, children who do not stutter and who had higher receptive vocabulary scores exhibited faster speech reaction times and a greater semantic priming effect, whereas no such relationships were found for children who stutter. Findings were taken to suggest that children who stutter may exhibit subtle difficulties with lexical encoding and that this difficulty with speech-language planning may be one variable that contributes to childhood stuttering.

Childhood stuttering and dissociations across linguistic domains

The purpose of this investigation was to evaluate the possible presence of dissociations in the speech and language skills of young children who do (CWS) and do not stutter (CWNS) using a correlation-based statistical procedure [Bates, E., Appelbaum, M., Salcedo, J., Saygin, A. P., & Pizzamiglio, L. (2003). Quantifying dissociations in neuropsychological research. Journal of Clinical and Experimental Neuropsychology, 25, 1128-1153]. Participants were 45 preschool CWS and 45 CWNS between the ages of 3;0 and 5;11 (years;months), with the two groups matched by age, gender, race, and parental socioeconomic status. Children participated in a parent-child interaction for the purpose of disfluency analysis and responded to four standardized speech-language tests for subsequent analyses as main dependent variables. Findings indicated that CWS were over three times more likely than CWNS to exhibit dissociations across speech-language domains, with 44 cases of dissociation for CWS and 14 for CWNS across 10 possible comparisons. Results suggest that there may be a subgroup of CWS who exhibit dissociations across speech-language domains, which may result in a greater susceptibility to breakdowns in speech fluency.

EDUCATIONAL OBJECTIVES

The reader will be able to: (1) summarize findings from previous studies examining differences in speech and language performance between children who do and do not stutter; (2) describe what is meant by "dissociations" in the speech and language skills of young children who do and do not stutter; and (3) discuss three hypotheses that could account for the present findings that suggest CWS, more often than CWNS, exhibit dissociations in their speech-language system.

Lexical development and retrieval in treating children who stutter

This article describes the role of lexical acquisition in stuttering by examining the research on word learning and interactions between semantics and syntax in typically developing children and children who stutter. The potential effects of linguistic mismatches, or dysynchronies in language skills, on the possible onset and development of stuttering are discussed. The article concludes with assessment and treatment considerations.

Nonword repetition abilities of children who stutter: an exploratory study

Past research has suggested that children who stutter (CWS) may have less well-developed language skills than fluent children, and that such relative linguistic deficiencies may play a role in precipitating their disfluencies. However, data to support this position are primarily derived from results of standardized diagnostic inventories, which are originally designed to identify frank language impairment. Nonword repetition has emerged as a more sensitive measure of children's linguistic abilities. In this exploratory study, eight CWS (mean age 5:10, range 4:3-8:4) were compared to eight normally developing children (ND) (mean age 5:9, range 4:1-8:4) in their ability to repeat the nonwords of the Children's Test of Nonword Repetition. CWS performed more poorly than NS on measures of Number of Words Correct and Number of Phoneme Errors at all nonword lengths, although statistical differences were observed only for 3-syllable nonwords. When lexical stress of the nonwords was varied to a non-English stress pattern, all participants repeated the stimuli with less accuracy, and the CWS again exhibited more errors than NS. Fluency for the CWS group did not change systematically with increasing nonword length. These preliminary findings are interpreted in light of a number of extant theories of the underlying deficit in childhood stuttering. We conclude that children who stutter may have diminished ability to remember and/or reproduce novel phonological sequences, and that further investigation into this possibility may shed light on the emergence and characteristics of childhood stuttering.

EDUCATIONAL OBJECTIVES

After completing this activity, the learner will: (1) be able to evaluate the research support for a linguistic component to stuttering; (2) describe the use of nonword repetition as an experimental and assessment device with children with SLI and children who stutter; (3) suggest future directions for research to further refine the potential role that linguistic encoding plays in the etiology and persistence of stuttering.

Childhood stuttering and speech disfluencies in relation to children's mean length of utterance: a preliminary study

The purpose of this study was to examine the influence of utterance length and complexity relative to the children's mean length of utterance (MLU) on stuttering-like disfluencies (SLDs) for children who stutter (CWS) and nonstuttering-like disfluencies (nonSLDs) for children who do not stutter (CWNS). Participants were 12 (3;1-5;11, years;months) children: 6 CWS and 6 age-matched (+/-5 months) CWNS, with equal numbers in each talker group (CWS and CWNS) exhibiting MLU from the lower to the upper end of normal limits. Data were based on audio-video recordings of each child in two separate settings (i.e., home and laboratory) during loosely structured, 30-min parent-child conversational interactions and analyzed in terms of each participant's utterance length, MLU, frequency and type of speech disfluency. Results indicate that utterances above children's MLU are more apt to be stuttered or disfluent and that both stuttering-like as well as nonstuttering-like disfluencies are most apt to occur on utterances that are both long and complex. Findings were taken to support the hypothesis that the relative "match" or "mismatch" between linguistic components of an utterance (i.e., utterance length and complexity) and a child's language proficiency (i.e., MLU) influences the frequency of the child's stuttering/speech disfluency.

EDUCATIONAL OBJECTIVES

The reader will learn about and be able to: (1) compare different procedures for assessing the relationship among stuttering, length and complexity of utterance, (2) describe the difference between relative and absolute measures of utterance length, (3) discuss the measurement and value of mean length of utterance and its possible contributions to childhood stuttering, and (4) describe how length and complexity influence nonstuttering-like disfluencies of children who stutter as well as the stuttering-like disfluencies of children who do not stutter.

Stuttering: a dynamic motor control disorder

The purpose of this review is to determine what neural mechanisms may be dysfunctional in stuttering. Three sources of evidence are reviewed. First, studies of dynamic inter-relationships among brain regions during normal speech and in persons who stutter (PWS) suggest that the timing of neural activity in different regions may be abnormal in PWS. Second, the brain lesions associated with acquired stuttering are reviewed. These indicate that in a high percentage of cases, the primary speech and language regions are not affected but lesions involve other structures, such as the basal ganglia, which may modulate the primary speech and language regions. Third, to characterize the motor control disorder in stuttering, similarities and differences from focal dystonias such as spasmodic dysphonia (SD) and Tourette's syndrome (TS) are reviewed. This review indicates that the central control abnormalities in stuttering are not due to disturbance in one particular brain region but rather a system dysfunction that interferes with rapid and dynamic speech processing for production.

EDUCATIONAL OBJECTIVES

The reader will be able to describe: (1) the similarities and differences between stuttering and other speech motor control disorders, (2) which brain lesions are most likely to produce acquired stuttering in adults, and (3) what type of brain abnormality most likely underlies stuttering.

A preliminary version of a computerized naming test for preschool children with language impairment

The most prevailing hypothesis regarding mechanisms behind specific language impairment today is the hypothesis of general limitations of processing capacity. Such an hypothesis can hardly be tested by available language assessment tools, especially not by instruments in use for clinical assessment of the lexical-semantic domain in children. Reduced naming speed is by some researchers considered as a core deficit in dyslexia and a better predictor of some aspects of reading proficiency than phonological processing. The overall purpose of the present study was therefore to develop a processing dependent tool, that could capture dynamic aspects of naming; response latencies, hesitation phenomena and contextual influence. We also present data from 30 children (4-6 years old) with normal language development. We believe that, with some modifications, the naming test has a potential of becoming a processing dependent measure of naming and a necessary complement to the assessment of vocabulary skills in children with language impairment.

The effects of contextualization on fluency in three groups of children

This study investigated the effects of contextualization on fluency in 12 school-age children who stutter (CWS), 11 children with language impairment (CLI), and 12 children with normally developing fluency skills (CNF). Participants in the study were between the ages of 8 and 12 years and were matched for age and sex. Four discourse samples were elicited by asking participants to (a) generate two scripts related to cooking and (b) retell two stories. Having objects or pictures immediately available contextualized a cooking task and a retelling task; another set of cooking and retelling tasks were decontextualized. Moments of disfluency were identified and coded for three primary categories of disfluency: stuttering-type, normal-type, and mazing. For CWS, a significant reduction in frequency of stuttering was noted in the contextualized script generation, and mazing occurred at a significantly higher frequency than did stuttering-type or normal-type disfluencies across the four tasks. For all three groups, both decontextualized conditions produced greater frequencies of normal-type disfluency and mazing. In addition, narrative retelling tasks yielded higher frequencies of disfluency than did the two cooking scripts.

A further analysis of narrative skills of children who stutter

This study tested for differences between children who stutter (CWS) and children with normally developing communication skills (CNC) on measures of narrative complexity and cohesion use in two narrative tasks. In addition, differences in stuttering frequency produced by CWS across tasks were measured. One story retelling and one story generation were elicited from eight CWS and eight age- and gender-matched CNC peers. Results revealed no significant differences between CWS and CNC for the measures of narrative complexity or cohesion use. However, significant differences were noted in stuttering frequency. Additionally, significant differences were found between the tasks for number of words, t-units, and episodes produced, as well as referents, conjunctions, and complete cohesive ties. Findings confirm that narrative abilities of CWS are similar to those of CNC, and that a retelling task produces longer and more elaborate narrative samples than does story generation. Directions for future research are discussed.

The genetic basis of persistence and recovery in stuttering

Although past research has provided evidence of a genetic component to the transmission of susceptibility to stuttering, the relationship between the genetic component to stuttering and persistence and recovery in the disorder has remained unclear. In an attempt to characterize this relationship, the immediate and extended families of 66 stuttering children were investigated to determine frequencies of cases of persistent and recovered stuttering. Pedigree analysis and segregation analysis were used to examine patterns of transmission. The following questions were investigated: 1. Is there a sex effect in recovery from stuttering? Here, we sought to test the hypothesis that females are more likely to recover than males, leading to the change in sex ratio from approximately 2:1 males to females close to onset of the disorder, to 4 or 5:1 in adulthood. 2. Is persistence/recovery in stuttering transmitted in families? If recovery/ persistence appears to be transmitted, (a) are recovered and persistent stuttering independent disorders?; (b) is recovery a genetically milder form of persistent stuttering?; or (c) is persistence/recovery transmitted independent of the primary susceptibility to stuttering? Results indicated sharply different sex ratios of persistent versus recovered stutterers in that recovery among females is more frequent than among males. It was found that recovery or persistence is indeed transmitted, and further, that recovery does not appear to be a genetically milder form of stuttering, nor do the two types of stuttering appear to be genetically independent disorders. Data are most consistent with the hypothesis that persistent and recovered stuttering possess a common genetic etiology, and that persistence is, in part, due to additional genetic factors. Segregation analyses supported these conclusions and provided statistical evidence for both a single major locus and polygenic component for persistent and recovered stuttering.

Phonological characteristics of children whose stuttering persisted or recovered

Among children who stutter, more will be identified with articulation/phonological deficiencies than among normally fluent children of the same ages. Most current literature has focused on phonological differences between those children who stutter and those who do not. The present study examines early phonological differences between young children whose stuttering persisted and those who recovered from early stuttering. Thirty-six children, 12 whose stuttering persisted, 12 who recovered early, and 12 who recovered later, had been assessed by means of the Assessment of Phonological Processes--Revised (Hodson, 1986) soon after they were identified as exhibiting stuttering. After many months of longitudinal evaluation of their stuttering that led to their classification into the three groups, the early phonological assessments of these children were re-examined to identify differences. Overall mean percentage of error scores as well as error scores on specific phonological patterns showed that the persistent group differed significantly from normally fluent control subjects matched by age and sex. Scores of the two groups who recovered and their matched controls, however, did not differ significantly. Although poor phonological ability in the early stage of stuttering appears to be a contributing factor to the differentiation of persistence and recovery, the wide individual variations in scores within groups suggest that additional factors are necessary for reliable prediction.

Genetics of stuttering: a critical review

The fact that stuttering runs in families has been documented over a long period and has led to speculations and research about the role of a genetic component to this disorder. Although the genetic factor cannot be proved by familial aggregation and twin studies alone, such research has continued to provide support for a relationship between stuttering and genetics. The purposes of this article are to review and critique the research in this area. The article first assesses research methodologies that have been employed in familial studies of stuttering. It proceeds to review and critique incidence, twin, and aggregation studies. In addition, it includes sections on subgroups, genetic models of stuttering, and implications for future research as well as for clinical work. With a focus on improved methodology and recent findings, a current perspective on our knowledge of the genetic component to stuttering is provided. Among other conclusions, the article emphasizes that failure to consider epidemiologic factors has probably biased previous results regarding the genetics of stuttering. New preliminary data also appear to provide evidence that spontaneous recovery and chronicity are influenced by genetic factors. Generally, however, the review of incidence and twin studies, as well as of evidence for the various inheritance models, confirms previous conclusions about the interaction between genetic and environmental factors in stuttering.

Treating the Child Who Stutters With Concomitant Language or Phonological Impairment

When children who stutter also demonstrate speech or language problems, establishing efficacious and reasonable therapy objectives can be difficult. This article discusses diagnostic considerations in identifying coexisting communication disorders and in differentiating between stuttering and secondary fluency disorders related to language formulation. A number of options for structuring therapy for coexisting problems are evaluated, including blended, lagged, and cycled approaches. Concerns implicit in the treatment of coexisting linguistic and fluency problems also are reviewed.