Decreased white-matter density in a left-sided fronto-temporal network in children with developmental language disorder: evidence for anatomical anomalies in a motor-language network

The neurophysiological and neuroanatomical foundations of developmental language disorder (DLD) are still a matter of dispute. A main argument is that children with DLD show atypical anatomical asymmetries of speech-relevant brain areas, which possibly affect efficient language processing. In contrast to previous anatomical studies in DLD children, this study employed voxel based morphometry (VBM) in order to search for brain anomalies outside the classical language areas. Children with DLD (n=21) and healthy children (n=21) matched for age, sex, hand preference, and education were studied using high-resolution MRI scans. Using a new variant of the voxel-based morphometry technique (augmented VBM), the brains of children with DLD and control children were compared with respect to white matter (WM) and grey matter (GM) differences. In addition, simple hand motor tests were used to uncover possible motor impairments in DLD children. We found decreased WM volumes in a left-hemispheric network comprising the motor cortex, the dorsal premotor cortex, the ventral premotor cortex, and the planum polare on the superior temporal gyrus. In addition, DLD children exhibited motor impairments in most of the applied motor tests. These results provide strong evidence that children with DLD have anomalous anatomy in a left-sided network comprising motor and language areas. Thus, this study supports the suggestion that motor and language functions are equally impaired because the underlying anatomical underpinnings are regionally identical.     

Simulating the Acquisition of Verb Inflection in Typically Developing Children and Children With Developmental Language Disorder in English and Spanish

Children with developmental language disorder (DLD) have significant deficits in language ability that cannot be attributed to neurological damage, hearing impairment, or intellectual disability. The symptoms displayed by children with DLD differ across languages. In English, DLD is often marked by severe difficulties acquiring verb inflection. Such difficulties are less apparent in languages with rich verb morphology like Spanish and Italian. Here we show how these differential profiles can be understood in terms of an interaction between properties of the input language, and the child's ability to learn predictive relations between linguistic elements that are separated within a sentence. We apply a simple associative learning model to sequential English and Spanish stimuli and show how the model's ability to associate cues occurring earlier in time with later outcomes affects the acquisition of verb inflection in English more than in Spanish. We relate this to the high frequency of the English bare form (which acts as a default) and the English process of question formation, which means that (unlike in Spanish) bare forms frequently occur in third-person singular contexts. Finally, we hypothesize that the pro-drop nature of Spanish makes it easier to associate person and number cues with the verb inflection than in English. Since the factors that conspire to make English verb inflection particularly challenging for learners with weak sequential learning abilities are much reduced or absent in Spanish, this provides an explanation for why learning Spanish verb inflection is relatively unaffected in children with DLD.     

The competition–compensation account of developmental language disorder

Children with developmental language disorder (DLD) regularly use the bare form of verbs (e.g., dance) instead of inflected forms (e.g., danced). We propose an account of this behavior in which processing difficulties of children with DLD disproportionally affect processing novel inflected verbs in their input. Limited experience with inflection in novel contexts leads the inflection to face stronger competition from alternatives. Competition is resolved through a compensatory behavior that involves producing a more accessible alternative: in English, the bare form. We formalize this hypothesis within a probabilistic model that trades off context-dependent versus independent processing. Results show an over-reliance on preceding stem contexts when retrieving the inflection in a model that has difficulty with processing novel inflected forms. We further show that following the introduction of a bias to store and retrieve forms with preceding contexts, generalization in the typically developing (TD) models remains more or less stable, while the same bias in the DLD models exaggerates difficulties with generalization. Together, the results suggest that inconsistent use of inflectional morphemes by children with DLD could stem from inferences they make on the basis of data containing fewer novel inflected forms. Our account extends these findings to suggest that problems with detecting a form in novel contexts combined with a bias to rely on familiar contexts when retrieving a form could explain sequential planning difficulties in children with DLD.

Research Highlights

• Generalization difficulties with inflectional morphemes in children with Developmental Language Disorder arise from these children's limited experience with novel inflected forms.
• Limited experience with a form in novel contexts could lead to a storage bias where retrieving a form often requires relying on familiar preceding stems.
• While generalization in typically developing models remains stable across a range of model parameters, certain parameter values in the impaired models exaggerate difficulties with generalization.
• Children with DLD compensate for these retrieval difficulties through accessibility-driven language production: they produce the most accessible form among the alternatives.

     

Exploring the contribution of the cerebral hemispheres to language comprehension deficits in adults with developmental language disorder

A divided visual field, priming paradigm was used to observe how adults who have a history of developmental language disorder (DLD) access lexically ambiguous words. The results show that sustained semantic access to subordinate word meanings (such as BANK-RIVER), which is seen in control subjects, is disrupted in the right cerebral hemisphere for this special population of readers. In the left hemisphere, only the most dominant meaning of the ambiguous word shows sustained priming in both controls and DLD participants. Therefore, for the DLD readers the subordinate meanings of words are not primed in either hemisphere and, thus, may not be available during online processing and integration of discourse. This right hemisphere lexical access deficit might contribute to the language comprehension difficulties exhibited by adult readers with a history of DLD.     

The processing of pseudohomophones by adults with a history of developmental language disabilities

Psuedohomophones are nonwords that sound like real words (e.g., BRANE). These items were used to gauge phonological access in adults who have experienced developmental language processing deficits (DLD). The standard effect for these items in lexical decision is an increase in response times over nonpseudohomophone nonwords. This disadvantage reflects phonological processing. In our first experiment the DLD group did not produce this pseudohomophone effect whereas in a second experiment they showed semantic priming effects when pseudohomophones were used as primes in lexical decision. The results therefore indicate that phonological processing of nonwords by adults with DLD can be uncovered under certain carefully controlled experimental conditions.     

Brain mechanisms and intelligence. Psychometric g and executive function

Sternberg [Sternberg, R.J. (1985). Beyond IQ: a triarchic theory of human intelligence. New York: Cambridge Univ. Press.] has proposed that the general intelligence, or the g factor, obtained when batteries of mental tests are factor analyzed, is a reflection of the fact that executive functions (EF) are common to all cognitive tests. Three lines of evidence that fail to support Sternberg's formulation are presented. First, in animal problem solving studies, there is only a modest degree of overlap between brain structures that are critical for g, and brain structures that have been identified as the rodent EF system. Second, children with attention deficit-hyperactivity disorder (ADHD), characterized by EF dysfunction, do not have IQ scores that are lower, on average, than children in the test standardization populations. Third, human frontal lobe patients often have clear EF deficits, but IQ (a next-best estimate of g) may be preserved. These findings cast serious doubt on the plausibility of Sternberg's formulation. Clarifying the distinction between psychometric g and EF can be important for understanding the differences between practical and psychometric intelligence.     

Working memory resources in young children with mathematical difficulties

Kyttälä, M., Aunio, P. & Hautamäki, J. (2010). Working memory resources in young children with mathematical difficulties. Scandinavian Journal of Psychology, 51 , 1–15.
Working memory (WM) ( Baddeley, 1986, 1997 ) is argued to be one of the most important cognitive resources underlying mathematical competence ( Geary, 2004 ). Research has established close links between WM deficits and mathematical difficulties. This study investigated the possible deficits in WM, language and fluid intelligence that seem to characterize 4- to 6-year-old children with poor early mathematical skills before formal mathematics education. Children with early mathematical difficulties showed poor performance in both verbal and visuospatial WM tasks as well as on language tests and a fluid intelligence test indicating a thoroughly lower cognitive base. Poor WM performance was not moderated by fluid intelligence, but the extent of WM deficits was related to language skills. The educational implications are discussed.     

Neuropsychological subgroups of adolescents with conduct disorder

Närhi, V., Lehto‐Salo, P., Ahonen, T. & Marttunen, M. (2010). Neuropsychological subgroups of adolescents with conduct disorder. Scandinavian Journal of Psychology, 51, 278–284. In group‐level studies adolescents with conduct disorder (CD) have been found to have deficiencies in verbal and executive functions. Teichner and Golden (2000) addressed the neuropsychological heterogeneity of CD, and hypothesized the existence of six neuropsychologically different subgroups. We used that theoretical basis to identify subgroups among 77 adolescents with CD and 48 controls. Among subjects with CD we identified subjects with no, diffuse, verbal and executive function deficits, but none with specific memory or visuo‐spatial deficits. In total, neuropsychological deficits altogether were more common among subjects with CD relative to controls, as were specific verbal deficits. Subgroups did not differ in gender distribution, comorbidity of psychiatric disorders, type or severity of CD, or number of psychosocial risk factors. Among subjects with CD, learning disabilities were common. CD is neuropsychologically a heterogeneous disorder, and neuropsychological deficits should be taken into account in assessing and planning interventions for adolescents with CD.     

MRI findings in boys with specific language impairment

Magnetic resonance imaging scans of specifically language-impaired (SLI) boys were examined to determine whether atypical cerebral findings could be documented in children whose primary deficits were in language skills. Clinical examination of the scans failed to reveal any visually obvious lesions or abnormalities. In contrast, measurement of the scans revealed atypical perisylvian asymmetries in most of these subjects. The distribution of perisylvian asymmetries in SLI subjects was significantly different from the distribution in controls (p less than .01). Measurement of other brain regions revealed that extraperisylvian areas were occasionally deviant in individual SLI subjects; but no one region was consistently deviant across the SLI group. Thus, only atypical perisylvian asymmetries were linked to the language disorder. These neuroanatomical findings suggest that a prenatal alteration of brain development underlies specific language impairment.     

Affect, Social Behavior, and the Brain in Williams Syndrome

ABSTRACT— Williams syndrome (WS) is a rare genetic disorder characterized by intellectual impairment and a distinctive physical and neuropsychological profile. Relative to their level of intellectual functioning, individuals with WS exhibit strengths in language and face recognition, with deficits in visual-spatial cognition. A heightened appetitive drive toward social interaction is a strong behavioral feature. Relative to other neurodevelopmental disorders, WS has a clearly defined genetic basis, together with a consistent neurocognitive profile of strengths and deficits. Thus, this disorder offers unique opportunities for elucidating gene–brain–behavior relationships. We focus on manifestations of the unusual social profile in WS, by examining data within and across levels of cognition, brain, and molecular genetics.     

Neuropsychological profile following suicide attempt by hanging: two adolescent case reports.

Hippocampal damage and amnesia following hypoxia and ischemia are described in the few published adult cases of suicide attempt by hanging. However, a recent review (Caine & Watson, 2000) suggests a variable pattern of brain involvement and neuropsychological impairments following hypoxic-ischemic injury that may or may not involve amnesia. To help clarify the impact of hanging on the developing brain, we examined neuropsychological functioning in two adolescents who survived suicide attempt by hanging. Despite differences in Glasgow Coma Scale (GCS), coma duration, and structural imaging findings, both patients had similar IQ (VIQ>PIQ) and presented with various combinations of deficits in expressive/receptive language, visual-constructional and perceptual ability, processing speed, attention, working memory, and/or executive functioning shortly after injury. In spite of their similarities, only one of the patients presented with classic amnesia symptoms in his early recovery. This patient was evaluated 1 year postinjury, and persistent deficits in processing speed and memory encoding were noted. Several hanging-related variables, including longer estimated hanging duration, greater weight, and severe airway edema, were thought to place this patient at increased risk for cognitive deficits. Clinical MRI scans of this patient obtained 6 weeks postinjury revealed mild volume loss as well as abnormalities in bilateral superior cortex. However, CT and MRI scans obtained throughout early recovery did not reveal overt evidence of injury to specific memory-related structures. Comprehensive neuropsychological evaluation of all adolescent survivors of suicide attempt by hanging is recommended, as a variety of postacute cognitive deficits were observed in these patients despite relatively short (相似文献   

Empathic deficits and alexithymia in trauma-related impulsive aggression

Our long term interest is to develop a developmental model of impulsive aggression based on a confluence of social, psychological and biological features. This approach incorporates neurobiological research, which has identified language processing deficits as a unique characteristic of impulsive aggressors and extends it to include emotional deficits. As an initial test of this hypothesis, we examined whether empathy and alexithymia were associated with impulsive aggression. Regressions were performed to explore the associations among impaired empathy, alexithymia, impulsive aggression, verbal and physical general aggression. Among impulsive aggressive veterans (n = 38) recruited from a VA trauma clinic, alexithymia predicted impulsive aggression and empathic deficits predicted verbal aggression. Neither emotional awareness deficit predicted general physical aggression in this middle-aged sample. Results suggested that empathic deficits were associated with general verbal aggression, but alexithymia was uniquely associated with impulsive aggression. Consideration of alexithymia in impulsive aggression has implications for its etiology, prevention and treatment. Published in 2008 by John Wiley & Sons, Ltd.     

Psychosocial functioning of children: Relations between personality subtypes and academic achievement

Five hundred children from ages 6 to 12 who had been referred for neuropsychological assessment were clustered into six subtypes using a kmeans technique applied to 10 PIC scales. Five of the six subtypes were virtually identical to subtypes identified in previous research (viz., normal, somatic concern, mild anxiety, externalized psychopathology, and internalized psychopathology). A sixth subtype (conduct disorder) was also found. Wide Range Achievement Test (WRAT) Reading and Spelling scores discriminated between normal, somatic concern, and conduct disorder subtypes on the one hand vs. the more disturbed externalized and internalized psychopathology subtypes on the other;the latter groups scored higher on these measures. The internalized psychopathology subtype also showed large discrepancies between reading vs. arithmetic and spelling vs. arithmetic. The results support the view that psychosocial functioning is related to assets and deficits in cognitive/academic functioning in children, and that particular patterns of such assets and deficits are related to particular forms of psychopathology.     

Neuropsychological profiles of six children with anoxic brain injury

Anoxic brain injury (ABI) often results in severe memory impairment and other cognitive and behavioral deficits, although limited information is available regarding pediatric cases. This study reported the neuropsychological outcomes in six children and adolescents who sustained ABI. Profiles were compared by mechanism of injury (ischemic vs. hypoxemic) and three cases were evaluated more than once. Severe intellectual, attention, memory, and behavioral impairments were observed in all six cases although academic achievement, internalizing behavioral problems, and visuospatial deficits were in general less severe than other cognitive and behavioral deficits. The longitudinal case studies varied but showed steady increases in memory and intellectual performance in the younger children with strongest improvement in nonverbal abilities and little change in parent-reported behavior. This study raises several possible hypotheses about specific cognitive and behavioral outcomes observed in pediatric ABI.     

What Causes Specific Language Impairment in Children?

ABSTRACT— Specific language impairment (SLI) is diagnosed when a child's language development is deficient for no obvious reason. For many years, there was a tendency to assume that SLI was caused by factors such as poor parenting, subtle brain damage around the time of birth, or transient hearing loss. Subsequently it became clear that these factors were far less important than genes in determining risk for SLI. A quest to find "the gene for SLI" was undertaken, but it soon became apparent that no single cause could account for all cases. Furthermore, although fascinating cases of SLI caused by a single mutation have been discovered, in most children the disorder has a more complex basis, with several genetic and environmental risk factors interacting. The clearest evidence for genetic effects has come from studies that diagnosed SLI using theoretically motivated measures of underlying cognitive deficits rather than conventional clinical criteria.     

Gyral morphology in the posterior Sylvian region in families affected by developmental language disorder

This study describes the family aggregation of gyral morphology in the posterior perisylvian region in families that contain one or more children with a developmental language disorder. The probands in these families were 8 male and 2 female children referred through therapy programs and schools for children with language and reading problems. Family members included both biological parents (10 m, 10 f) and all available siblings (6 m, 4 f). Gyral morphology in the members of these families was compared with control subjects (10 m, 10 f) who were without a personal or family history of developmental language disorders. Gyral morphology was evaluated using T1-weighted sagittal scans from a GE Signa 1.5T magnet, 5 mm consecutive slices through the full brain volume. A less common type of Sylvian fissure morphology was more frequently found in the hemispheres of language-disordered subjects and their first-degree relatives than in control subjects. In addition, the pattern of Sylvian fissure morphology across generations within the families suggests that this feature might be inherited from either parent. The elevated rate of extra gyri in the posterior perisylvian region in families affected by language disorder links an anomaly within a language-related brain region with familial risk for this disorder.     

Linguistic and nonlinguistic impairments in writing: a comparison of patients with focal and multifocal CNS disorders

The hypothesis that the language disorder in Alzheimer's disease (AD) depends on degenerative brain changes in classical left-hemisphere language zones was tested by comparing the written language performances of a group of AD patients with mild-moderate dementia and left-hemisphere stroke patients with equally severe naming and auditory comprehension deficits who were in varying stages of recovery from Wernicke's aphasia. The results indicated significant qualitative group differences in performances between tasks and in errors within tasks. The findings are consistent with hypothesized disruption of more diffusely organized neurolinguistic systems in AD. The hypothesis that the language disorder in AD represents an exaggeration of the pattern of language change in normal aging was also examined by comparing the performances of AD patients to the changes that occur with very advanced normal aging. The data indicate convergence between AD and very elderly healthy subjects in some aspects of written language production.     

Quantitative and qualitative evaluation of neuromotor behaviour in children with a specific speech and language disorder

Several studies have described problems in a wide area of motor functions in language impaired children. The purpose of this study was to identify the nature of the motor deficits in two subgroups of language impaired children. A standard neurological examination was performed on 18 children with an expressive language disorder and 21 children with a receptive language disorder. The motor performance of the language disordered children was compared with the motor performance of 23 normal children. The standard neurological examination allowed for a qualitative and quantitative assessment of five specific neurological subsystems. Handedness was determined for all children. The language impaired children had more motor problems than the control children on most neurological subsystems. There were few statistically significant differences between the two groups of language impaired children. An excess in left‐handedness was established in the group of children with a receptive language disorder. There was a co‐occurrence of verbal and non‐verbal deficits in language impaired children. As these motor problems put an additional burden on the development of language impaired children, they should be diagnosed as early as possible. Copyright © 2002 John Wiley & Sons, Ltd.     

Language Abilities in Children with Attention Deficit Hyperactivity Disorder, Reading Disabilities, and Normal Controls

Research has demonstrated a high prevalence of language impairments (LI) and reading disabilities (RD) in children with attention deficit hyperactivity disorder (ADHD). Since RD is also associated with LI, it is unclear whether the language impairments are specific to ADHD or associated with comorbid RD. The language abilities of ADHD children with and without RD were investigated in a task requiring recall of a lengthy narrative, and in tests assessing knowledge of the semantic aspects of language. The study was conducted with 50 boys—14 ADHD, 14 ADHD + RD, 8 RD, and 14 normal controls, aged 7 to 11. Children with ADHD (ADHD-only, ADHD + RD) exhibited difficulties in organizing and monitoring their story retelling. Children with RD (RD-only, ADHD + RD) demonstrated deficits in receptive and expressive semantic language abilities on the language processing tests. The comorbid group (ADHD + RD) exhibited the deficits of both ADHD and RD children. The deficiencies of ADHD children are consistent with higher-order executive function deficits while the deficits of RD children are consistent with deficits in the basic semantics of language processing.     

Pragmatic aspects of communication and language comprehension in groups of children differentiated by teacher ratings of inattention and hyperactivity

Children with attention‐deficit hyperactivity disorder (ADHD) experience pragmatic language deficits, but it is not known whether these difficulties are primarily associated with high levels of inattention, hyperactivity, or both. We investigated pragmatic aspects of communication and language comprehension in relation to poor attention and/or high hyperactivity in a nondiagnosed population of 7‐ to 11‐year olds. Classroom teachers rated their pupils' attention and hyperactivity/impulsivity on the ADD‐H Comprehensive Teacher Rating scale (ACTeRS). Three groups were formed: children with poor attention and low hyperactivity (poor attention group), children with good attention and high hyperactivity (high hyperactivity group), and children with both poor attention and high hyperactivity (poor attention/high hyperactivity group). Their performance was compared with that of same‐age controls in two studies: Study 1 (N = 94) investigated the comprehension of figurative language in and out of context and Study 2 (N = 100) investigated the pragmatic aspects of communication using the Children's Communication Checklist – Second Edition. Two groups, the poor attention and the poor attention/high hyperactivity groups, were impaired in both their comprehension of figurative language and their communication skills. The high hyperactivity group was impaired in their comprehension of figurative language but they did not exhibit communication impairments. The findings extend work with clinical populations of children with ADHD: even in a nondiagnosed sample of children, poor attention and elevated levels of hyperactivity are associated with pragmatic language weaknesses.