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Progressive supranuclear palsy (PSP) is a progressive neurological condition, whose main features include supranuclear gaze palsy, frequent falls, bradykinesia, axial rigidity, cognitive decline and communication impairments. Even though communication impairments are early and prominent manifestations, there is a significant lack of research on the nature of these impairments in PSP and the role of speech-language pathologists (SLPs). This tutorial article aims to describe the communication impairments observed in people with PSP; provide clinical guidelines for SLPs when assessing motor speech, language and other communication impairments; and to present facilitation and compensation approaches to treatment for people with PSP. The predominant motor speech impairment is mixed dysarthria, but there is a lack of consensus about the classification of language impairments. The involvement of SLPs in the assessment and treatment of people with PSP should be early, on-going and in collaboration with other health professionals, with the primary focus of maintaining quality of life for these patients and their family members., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Unlabelled: Previous findings from a case report led to the argument of whether other patients with neurofibromatosis type 1 (NF1) may have abnormal central auditory function, particularly auditory temporal processing. We hypothesized that it is associated with language and learning disabilities in this population. The aim of this study was to measure central auditory temporal function in NF1 patients and correlate it with the results of language evaluation tests. A descriptive/comparative study including 25 NF1 individuals and 22 healthy controls compared their performances on audiometric evaluation and auditory behavioral testing (Sequential Verbal Memory, Sequential Non-Verbal Memory, Frequency Pattern, Duration Pattern, and Gaps in Noise Tests). To assess language performance, two tests (phonological and syntactic awareness) were also conducted. The study showed that all participants had normal peripheral acoustic hearing. Differences were found between the NF1 and control groups in the temporal auditory processing tests [Sequential Verbal Memory (P=0.009), Sequential Non-Verbal Memory (P=0.028), Frequency Patterns (P=0.001), Duration Patterns (P=0.000), and Gaps in Noise (P=0.000)] and in language tests. The results of Pearson correlation analysis demonstrated the presence of positive correlations between the phonological awareness test and Frequency Patterns humming (r=0.560, P=0.001), Frequency Patterns labeling (r=0.415, P=0.022) and Duration Pattern humming (r=0.569, P=0.001). These results suggest that the neurofibromin deficiency found in NF1 patients is associated with auditory temporal processing deficits, which may contribute to the cognitive impairment, learning disabilities, and attention deficits that are common in this disorder., Learning Outcomes: The reader will be able to: (1) describe the auditory temporal processing in patients with neurofibromatosis type 1; and (2) describe the impact of the auditory temporal deficits in language in this population., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Unlabelled: Prader-Willi syndrome (PWS), most recognized for the hallmark hyperphagia and food preoccupations, is caused by the absence of expression of the paternally active genes in the q11-13 region of chromosome 15. Since the recognition of PWS as a genetic disorder, most research has focused primarily on the medical, genetic, and behavioral aspects of the syndrome. Extensive research has not been conducted on the cognitive, speech, and language abilities in PWS. In addition, language differences with regard to genetic mechanism of PWS have not been well investigated. To date, research indicates overall language ability is markedly below chronological age with expressive language more impaired than receptive language in people with PWS. Thus, the aim of the present study was to further characterize expressive and receptive language ability in 35 participants with PWS and compare functioning by genetic subtype using the Clinical Evaluation of Language Fundamentals-4 (CELF-IV). Results indicate that core language ability is significantly impaired in PWS and both expressive and receptive abilities are significantly lower than verbal intelligence. In addition, participants with the maternal uniparental disomy (mUPD) genetic subtype exhibit discrepant language functioning with higher expressive vs. receptive language abilities. Future research is needed to further examine language functioning in larger genetic subtype participant samples using additional descriptive measures. Further work should also delineate findings with respect to size of the paternal deletion (Type 1 and Type 2 deletions) and explore how overexpression of maternally expressed genes in the 15q11-13 region may relate to verbal ability., Learning Outcomes: After reading this article, the reader will be able to: (1) summarize primary characteristics of Prader-Willi syndrome (PWS), (2) describe differentiating characteristics for the PWS genetic subtypes, (3) recall limited research regarding language functioning in PWS to date, (4) summarize potential genetic variations of language ability in Prader-Willi syndrome, and (5) summarize language ability in PWS with respect to adaptive functioning., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Unlabelled: We compared the processing of natural language quantifiers in a group of patients with schizophrenia and a healthy control group. In both groups, the difficulty of the quantifiers was consistent with computational predictions, and patients with schizophrenia took more time to solve the problems. However, they were significantly less accurate only with proportional quantifiers, like more than half. This can be explained by noting that, according to the complexity perspective, only proportional quantifiers require working memory engagement., Learning Outcomes: (1) Working memory deficits can be a source of language disorders in schizophrenia. (2) Processing of proportional quantifiers, like more than half or less than half involves working memory. (3) Patients with schizophrenia are less accurate only with proportional quantifiers, like more than half. (4) This result support the computational model of quantifiers processing., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Unlabelled: There are many distinct forms of dementia whose pharmacological and behavioral management differ. Differential diagnosis among the dementia variants currently relies upon a weighted combination of genetic and protein biomarkers, neuroanatomical integrity, and behavior. Diagnostic specificity is complicated by a high degree of overlap in the initial presenting symptoms across dementia subtypes. For this reason, reliable markers are of considerable diagnostic value. Communication disorders have proven to be among the strongest predictors for discriminating among dementia subtypes. As such, speech-language pathologists may be poised to make an increasingly visible contribution to dementia diagnosis and its ongoing management. The value and durability of this potential contribution, however, demands an improved discipline-wide knowledge base about the unique features associated with different dementia variants. To this end we provide an overview of cognition, language, and clinical pathological features of four of the most common non-Alzheimer's dementias: frontotemporal dementia, vascular dementia, Lewy body disease dementia, and Parkinson's disease dementia., Learning Outcomes: Readers will learn characteristics and distinguishing features of several non-Alzheimer's dementias, including Parkinson's disease dementia, frontotemporal dementia, vascular dementia, and Lewy body dementia. Readers will also learn to distinguish between several variants of frontotemporal dementia. Finally, readers will gain knowledge of the term primary progressive aphasia as it relates to the aforementioned dementia etiologies., (Copyright 2010 Elsevier Inc. All rights reserved.)

Unlabelled: Premature infants have a disproportionately increased risk for brain injury based on several mechanisms including intraventricular hemorrhage, ischemia and the vulnerability of developing neuronal progenitor cells. Injury to the developing brain often results in neurologic abnormalities that can be correlated with a structural lesion; however more subtle injury may result in disruption of critical neural pathways. There also appears to be an important relationship between brain injury in the cortex and the growth and developing cerebellum. Although the survival rate for premature has improved over the past decade, researchers remain concerned about the risk for adverse neurocognitive functioning in these early childhood, including an increased risk for cerebral palsy, cognitive impairment, speech and language delay and sensory dysfunction., Learning Outcomes: After this activity, the learner will be able to (1) identify potential causes of brain injury in the premature infant, (2) understand that the maturational process for the human brain continues throughout gestation, (3) identify risk factors for adverse neurocognitive functioning in premature infants, and (4) identify abnormalities on central nervous system neuroimaging studies that correlate with an increased risk for adverse neurodevelopmental outcome in premature infants.

Unlabelled: Auditory processing disorder (APD) describes a mixed and poorly understood listening problem characterised by poor speech perception, especially in challenging environments. APD may include an inherited component, and this may be major, but studies reviewed here of children with long-term otitis media with effusion (OME) provide strong evidence for changes in auditory processing acquired through altered experience (deprivation) and brain plasticity. Whether inherited or acquired, it is suggested that APD may be reversed by active learning. Training tunes both bottom-up and top-down neural mechanisms, some that are specific to the trained stimulus and some that reflect more generalised arousal. APD and its treatment therefore provide examples of brain plasticity working either in a negative or in a positive way to modulate listening., Learning Outcomes: (1) Readers will be able to discuss APD in the context of inheritance and experience. (2) Readers will be able to explain how OME has been shown to alter auditory processing. (3) Readers will be able to list examples of good and bad brain plasticity. (4) Readers will be able to explain what auditory learning is, list some of its properties, and provide examples of its application in therapy for communication disorders.

Unlabelled: While much attention has been given to documenting the language skills of verbal children with autism, the basic speech sound development patterns of severely language-impaired children with autism are unknown. Previous research has shown that certain consonants are generally produced earlier in development than other consonants, both in typically developing children and in children with language-learning impairments. While several large studies indicate that children with autism who have strong verbal skills have intact phonological development, there is some evidence that children with autism who are more severely language impaired may have abnormal phonological production. This study documents the speech sound development of non-verbal and minimally verbal children with autism. Prompts were administered for each individual speech sound while spontaneous and imitated sounds were recorded and scored. Results indicate that children with autism show the same general speech sound production patterns as typically developing and language-learning impaired children., Learning Outcomes: Individuals who read this manuscript will obtain information regarding: (1) normal phonological development, (2) a comparison of speech sound production of a group of 14 children with a diagnosis of autism spectrum disorder with the production of a group of 10 typically developing children, and (3) comparisons of imitated and spontaneous sound production of the children diagnosed with autism spectrum disorder.

Unlabelled: Non-adjacent dependencies characterize numerous features of English syntax, including certain verb tense structures and subject-verb agreement. This study utilized an artificial language paradigm to examine the contribution of item variability to the learning of these types of dependencies. Adult subjects with and without language-based learning disabilities listened to strings of three non-words for which the first and third elements had a dependent relationship. In the low variability condition, 12 non-words occurred in the middle position, and in the high variability condition, 24 non-words occurred in this position. Non-disabled adults were able to learn the non-adjacent contingencies and generalize the underlying structure to new strings, but only when variability was high. Adults with language-based learning disabilities did not perform above chance levels under either variability condition. Thus, this group showed poor sensitivity to statistical information in speech input that both infants and non-disabled adults are known to track., Learning Outcomes: As a result of this activity, the reader will: (1) understand the advantages of using an artificial language to investigate language learning; (2) become familiar with a paradigm for studying the rapid learning of syntactic contingencies; (3) comprehend how the ability to map language structure differs for non-disabled adults and adults with a history of language/learning disability as a function of variability in the input the listener receives.

Unlabelled: The lexical-semantic and syntactic abilities of a group of individuals with chronic nonthalamic subcortical (NS) lesions following stroke (n=6) were investigated using the Western Aphasia Battery (WAB) picture description task [Kertesz, A. (1982). The Western aphasia battery. New York: Grune and Stratton] and compared with those of a group of subjects with Huntington's Disease (HD) (n=6) and a nonneurologically impaired control group (n=6) matched for age, sex, and educational level. The performance of the NS and HD subjects did not differ significantly from the well controls on measures of lexical-semantic abilities. NS and HD subjects provided as much information about the target picture as control subjects, but produced fewer action information units. Analysis of syntactic abilities revealed that the HD subjects produced significantly more grammatical errors than both the NS and control subjects and that the NS group performed in a similar manner to control subjects. These findings are considered in terms of current theories of subcortical language function., Learning Outcomes: As a result of this activity, the reader will obtain information about the debate surrounding the role of subcortical language mechanisms and be provided with new information on the comparative picture description abilities of individuals with known vascular and degenerative subcortical pathologies and healthy control participants.

Unlabelled: This report reviews the speech and language development of a child who, as result of complete subglottic stenosis, was aphonic from birth until 2 years and 11 months of age at which time laryngotracheal reconstruction provided normal respiration. The boy had congenital subglottic stenosis requiring neonatal tracheostomy. The congenital subglottic stenosis progressed to complete subglottic stenosis during the neonatal period. The child's speech and language development was monitored for a 24-week period following airway reconstruction., Learning Outcomes: The reader will learn about and be able to describe: (1) the speech and language development of a child who was aphonic from birth until 35 months of age, (2) the effects of surgical repair of a tracheotomy on the child's speech and language development, (3) the likely importance of babbling in speech and language development.

Unlabelled: This paper reviews research on the consequences of prenatal exposure to alcohol and cocaine on children's speech, language, hearing, and cognitive development. The review shows that cognitive impairment, learning disabilities, and behavioral disorders are the central nervous system manifestations of fetal alcohol syndrome (FAS), and cranio-facial abnormalities are also present. Delays in language acquisition, as well as receptive and expressive language deficits, are commonly reported. The cranio-facial abnormalities of FAS, which sometimes include cleft palate, make the child prone to otitis media with effusion and conductive hearing loss. The family environment in which one or both parents is a heavy alcohol user presents challenges to a child with normal intelligence, but may be especially deleterious to the child with mental retardation. Prenatal exposure to cocaine results in subtle cognitive disabilities when measured at 4 years of age. The cognitive effects may be ameliorated by a stimulating and sensitive care-giving environment. A small, deleterious "cocaine-effect" is also seen in speech and language development. The child with prenatal exposure to cocaine may be considered at increased risk for language delay or disorder. There is no evidence that prenatal cocaine exposure by itself is a risk factor for sensorineural hearing impairment, although auditory evoked potentials from the brainstem and cortex suggest some abnormalities in central auditory processing, at least during the newborn period. The strong effect of the home environment for ameliorating the effects of prenatal cocaine-exposure suggests that a family-focused approach for cognitive, language, and social-emotional habilitation would be beneficial to all., Learning Outcomes: The learner will be able to describe the major features of fetal alcohol syndrome and how they relate to speech, language, hearing, and cognitive disorders. The learner will review the literature and determine research needs with respect to language, speech, and hearing among infants and children with fetal alcohol syndrome. Similarly, the learner will distinguish the outcomes of prenatal alcohol-exposure from those of prenatal cocaine-exposure. The learner will summarize the controversy regarding the possible stigmatization of cocaine-exposed infants. The learner will summarize the speech, language, and hearing effects of prenatal cocaine-exposure.

Unlabelled: The communication of people with autism spectrum disorder (ASD) is characterized by a qualitative impairment in verbal and non-verbal communication. In past decades a growing body of descriptive studies has appeared on language and communication problems in ASD. Reviews suggest that the development of formal and semantic aspects is relatively spared, whereas pragmatic skills are considered to be specifically impaired. This unique profile was interpreted mainly within the framework of the theory of mind hypothesis, which links the social-communicative problems of people with autism to an incapacity to attribute mental states to themselves and others. This approach has proven useful, but has also left many questions unanswered. In more recent publications, limited intentionality and symbol formation have been identified as core problems in ASD. Problems in symbol formation in particular might be better understood from the viewpoint of the central coherence hypothesis, which conceptualizes ASD as a weaker drive for the integration of information. Possible links between cognitive findings and communication evoke new perspectives with respect to the complex of communication problems in ASD., Learning Outcomes: The reader of this manuscript will be able to (1) describe the communication deficit in ASD; (2) discuss the central coherence account of ASD in relation to problems in sense-making; and (3) explain how these difficulties might lead to problems in communication in autism.

Unlabelled: This investigation examined the relationship between social pragmatics, social self-esteem, and language in children with specific language impairment (SLI) and in their age-matched peers (7-10 years). The children with SLI indicated significantly poorer social cognitive knowledge than their typically developing peers. They showed low social, but not academic self-esteem. They often used inappropriate negotiation and conflict resolution strategies. Their errors reflect some qualitative differences from those of the typically developing children (e.g., children with SLI use more nonverbal strategies, demonstrate passive/withdrawn behavior, etc.). Our data show that these children's social pragmatic deficit is not causally related to their language impairment; the two problems are co-occurring. Further, the parents and teachers of the children with SLI indicated different views regarding these children's social relations. Although the parents expressed major concerns about their children's social competence, the teachers did not notice this problem., Learning Outcomes: The reader will be able to summarize, critically analyze, and interpret the findings from existing research on social cognition and its relationship with language abilities in children with specific language impairment. Further, the reader will gain an understanding of the importance of applying intervention procedures that facilitate the use of language in different social situations, and the necessity of increasing parent-teacher communication in schools.

Unlabelled: This study tested the hypothesis that early language experience facilitates the development of language-specific perceptual weighting strategies believed to be critical for accessing phonetic structure. In turn, that structure allows for efficient storage and retrieval of words in verbal working memory, which is necessary for sentence comprehension. Participants were forty-nine 5-year-olds, evenly distributed among four groups: those with chronic otitis media with effusion (OME), low socio-economic status (low-SES), both conditions (both), or neither condition (control). All children participated in tasks of speech perception and phonological awareness. Children in the control and OME groups participated in additional tasks examining verbal working memory, sentence comprehension, and temporal processing. The temporal-processing task tested the hypothesis that any deficits observed on the language-related tasks could be explained by temporal-processing deficits. Children in the three experimental groups demonstrated similar results to each other, but different from the control group for speech perception and phonological awareness. Children in the OME group differed from those in the control group on tasks involving verbal working memory and sentence comprehension, but not temporal processing. Overall these results supported the major hypothesis explored, but failed to support the hypothesis that language problems are explained to any extent by temporal-processing problems., Learning Outcomes: As a result of this activity, the participant will be able to (1) Explain the relation between language experience and the development of mature speech perception strategies, phonological awareness, verbal working memory, and syntactic comprehension. (2) Name at least three populations of individuals who exhibit delays in the development of mature speech perception strategies, phonological awareness, verbal working memory, and syntactic comprehension, and explain why these delays exist for each group. (3) Point out why perceptual strategies for speech are different for different languages. (4) Describe Baddeley's model [A.D. Baddeley, The development of the concept of working memory: implications and contributions of neuropsychology, in: G. Vallar, T. Shallice (Eds.), Neuropsychological Impairments of Short-term Memory, Cambridge University Press, New York, 1990, p. 54] of verbal working memory.

Six adolescents with traumatic brain injury and six adolescents who had been hospitalized for an illness or injury not affecting the brain were administered two narrative tasks designed to vary in their demand for spontaneous organization of information and minimize the requirement for new learning. The discourse topics--a description of each subject's injury and hospitalization, and a re-telling of a current event--were chosen to be representative of discourse in adolescent daily living. Narratives produced by subjects in each group were compared between the two tasks on measures of coherence and cohesion. Subjects in both groups produced significantly more coherent and cohesive narratives in the personal event task than in the current event task, and there was no significant difference between groups. The results are discussed in relation to face validity of language tasks for adolescents, and the multiple factors contributing to adolescent social discourse.

Sources of difficulty in comprehending conversational questions for individuals with autism may be multifarious, given the complexity of the disorder. This study investigated success in responding to naturalistic conversational questions by six young adults with autism, using a quantitative discourse analytic method. Subjects, aged 19-21, who were able to converse in at least simple sentences, were engaged in conversation about events and activities in their lives. From the transcripts of these conversations, four types of questions were isolated for analysis: more than seven words in length; multiclausal; requiring inference; and indirect requests for information. It was predicted that inference-based questions would be more difficult than the other types. Findings did not support this prediction. All four types showed a higher failure rate than the overall failure rate for responses to conversational questions. Clinical implications include the need for conversational assessment of receptive language functioning for individuals with autism. Suggestions for such assessments are provided.

Although neuropsychological localization constitutes the principal approach to the study of language disorders, there is reason to think it may not be entirely correct. Recent anatomical studies suggest that cognitive brain functions do not localize to precise anatomical locations. Connectionist (parallel distributed processing) approaches to the study of language, which emphasize the distributed nature of computational processes, may help explain the variability found in these anatomical studies, and provide a new way to approach the neurological study of language. This combined computational and empirical method focuses on the interplay between a computational model and the appropriate neurological, neuropsychological, and speech and language data, the whole couched in connectionist mechanisms that map naturally to what is known of the neurophysiological structure of the brain. This paper introduces the concepts of connectionist modeling, with emphasis on their use in understanding language disorders.

This study presents a set of narrative and non-narrative tasks and analytic procedures for examining the discourse development of children with perinatal brain injury and typically developing children. Three oral discourse genres were collected at ages 5, 6, and 7: script, picture description, and replica play narration. Genre performances were assessed for the presence of hypothesized genre features. Results suggest these tasks and procedures are able to characterize development in discourse abilities for both a normative group and for children with perinatal brain injury. The group of children with brain injury produced shorter discourse performance with more off-task talk. This group also showed difficulty in fully differentiating the various genre types and in creating integrated discourse performances. However, most of these children demonstrated considerable growth in control of genre features over this time period. The possible utility of these tasks and procedures for clinical assessment is discussed.

The communicative abilities of six sets of same-sex, dizygotic twins (CAs 2;1-4;1) were examined. In each dyad, one sibling had a strong positive history of recurrent otitis media (ROM), while the other twin had a negative or minimal history of ROM. Standardized test performance and spontaneous speech and language abilities were examined. Results suggest that although a history of ROM is associated with lowered receptive vocabulary scores in these dyads, no consistent effects of ROM could be detected in expressive speech and language tasks. In two dyads, the ROM-positive twin did score lower on articulation and language measures; however, in two dyads, children with equivalent histories of ROM outscored their ROM-negative siblings. In the remaining dyads, little difference was observed between the siblings on the measures we used. We suggest that the effects of ROM on communicative development are complex and subtle, and that control of home and day care environment may minimize some of the previously documented associations between ROM and speech-language development.

This study compares language abilities in three groups of children who were born prematurely: children with bilateral spastic cerebral palsy associated with perinatal injury to the periventricular white matter of the brain; a group with similar brain injury but no motor impairment; and a group of controls with no brain injuries. Six boys in each group were 36 to 39 months of age at the time of the study. All achieved a standard score above 80 on the McCarthy Scales of Children's Abilities at the same age. Language samples, generated during parent-child interaction, were analyzed using the Child Language Data Exchange System. The size and diversity of the lexicon was assessed using types and tokens per minute. Morpho-syntactic skills were assessed using number of grammatical morphemes, mean length of utterance and the Index of Productive Syntax. Verbal productivity was assessed using number of utterances per minute. No significant differences were observed among any of the groups on any measure. Measures of the lexicon and morpho-syntactic skills were highly correlated with the scores on the McCarthy Scales of Children's Abilities. The data demonstrated that specific language impairments were not associated with cerebral palsy or brain injury after prematurity at this early stage of language development. However, individual children within each of the groups had delays in skill attainment that warranted language intervention.

Aphasia coupled with amusia is reported in a 73-year-old male musician who was a lawyer by profession. This condition followed an ischemic stroke in the lateral aspect of the parieto-occipital region of the left hemisphere. The patient's music production exhibits jargon amusia, similar to that in his verbal production. This case supports the thesis that language and music may share a common hemisphere.

This paper surveys the literature on prenatal alcohol exposure. The focus is on studies of speech, language, and communication skills evidenced by children diagnosed with fetal alcohol syndrome and fetal alcohol effects. Concomitant physical, behavioral, intellectual, and learning patterns are reviewed. Symptoms presented by alcohol-exposed children are compared to those seen in other developmentally delayed children. Future needs in areas of identification, assessment, and treatment are discussed.

A series of tables is presented as a diagnostic aid for the clinician when presented with a client who has a genetic syndrome. Information is provided on physical features, inheritance pattern, incidence rate, speech and language characteristics, and references. The speech and language clinician is cautioned that there is great variation of expression in genetic syndromes. However, the tables can be used to find those characteristics identified in the literature as manifested in a particular genetic syndrome.

The present paper reviews, outlines, and explores the literature concerned with the speech-language disorder of childhood autism. The problems of communication of the autistic child are compared and contrasted with those of children with a variety of other language disorders (e.g. receptive developmental dysphasia). Based upon the review of normal preverbal communicatory and symbolic development, it is concluded that childhood autism involves a pervasive language disorder encompassing communication in general, as well as certain symbolic-representational abilities necessary for language. An overview of the attempts to teach speech to autistic children in then undertaken with special emphasis on the possible implications of developmental knowledge for these training pursuits. Finally, the role of neurologic substrates in the language and communication disorder of autism is presented.

Despite the acceptance of perseveration as a characteristic sign of disturbed CNS functioning, objective data relative to its nature and occurrence are noticeably lacking. Data obtained in this study, not unexpectedly, indicate that perseverative responses occur more often in brain-injured than in normal subjects. The brain-injured subject most likely to evidence perseveration appeared to be one who (1) had suffered a CVA (2) less than 6 months ago that (3) resulted in aphasia. Two types of perseveration, repetitious and continuous, were noted in the responses of the brain-injured with higher incidences of the repetitious type occurring. It was felt that the behavioral definitions used to differentiate between repetitious and continuous perseveration allowed for reliable judgments between observers.

Interviewer status (high vs. low) and anticipated evaluation (positive vs. negative) were manipulated orthogonally to test competing predictions derived from Hull-Spence and Mahl-Osgoood drive theory hypotheses. The effects of question specificity, interview topic, and interview segment were examined concomitantly. Verbal behavior measures were total words per interviewee response, mean segmental TTR (25), partial mean segmental TTR (25), and ratio of disfluency per response. Results for disfluency tended to support the Mahl-Osgood hypothesis. Lexical diversity results offered weak support for the Hull-Spence hypothesis. Results for verbal productivity failed to support either of the hypotheses and were interpreted as possibly supporting the Duffy-Malmo inverted U hypothesis. Generally, the results suggested that the unitary construct "drive" may be inadequate for explaining the effects of specific situational variables upon verbal behavior.

This investigation determined the influence of modeling on the complexity of language in 5-year-old youngsters, and the effect of simple and complex language usage on the occurrence and topography of disfluency. Forty children balanced for age, sex, and educational level served as subjects, and a repeated measures design was implemented to examine changes in linguistic complexity and disfluency between "simple" and "complex" language modeling conditions. The investigation demonstrated a significant modeling effect and suggested a significant relationship between linguistic complexity and disfluency in children. The results are discussed in terms of grammatical load and its possible effect on speech interruption.

The acquisition of language is discussed in relation to two specific perceptual processes: first, identification and discrimination of recurring aspects of an experience, and second, integration of the language form with the specific aspect of the event being represented. The analysis of the language of a child with perceptual and integrative deficits revealed expressive use of language without comprehension and limited knowledge of concepts. Explanations of these behaviors are presented in light of the child's perceptual and integrative dysfunctions. Implications for clinical management of a perceptually based language disorder are discussed.