Online measures of basic language skills in children with early focal brain lesions

A curious case of retrogenesis in language: Automated analysis of language patterns observed in dementia patients and young children

Introduction

While linguistic retrogenesis has been extensively investigated in the neuroscientific and behavioral literature, there has been little work on retrogenesis using computerized approaches to language analysis.

Methods

We bridge this gap by introducing a method based on comparing output of a pre-trained neural language model (NLM) with an artificially degraded version of itself to examine the transcripts of speech produced by seniors with and without dementia and healthy children during spontaneous language tasks. We compare a range of linguistic characteristics including language model perplexity, syntactic complexity, lexical frequency and part-of-speech use across these groups.

Results

Our results indicate that healthy seniors and children older than 8 years share similar linguistic characteristics, as do dementia patients and children who are younger than 8 years.

Discussion

Our study aligns with the growing evidence that language deterioration in dementia mirrors language acquisition in development using computational linguistic methods based on NLMs. This insight underscores the importance of further research to refine its application in guiding developmentally appropriate patient care, particularly in early stages.

New insights from children with early focal brain injury: Lessons to be learned from examining STEM-related skills

The study of cognitive development in children with early brain injury reveals crucial information about the developing brain and its plasticity. However, information on long-term outcomes of these children, especially in domains relevant to science, technology, engineering, and math (STEM) remains limited. In the current review, our goal is to address the existing research on cognitive development of children with pre- or perinatal focal brain lesion (PL) as it relates to children's STEM-related skills and suggest future work that could shed further light on the developmental trajectories of children with PL. We argue that examining STEM-related development in children with PL will have broader implications for our understanding of the nature of the plasticity children with PL exhibit as well as address theoretical questions in the field regarding the foundation skills for STEM, including visuospatial and mathematical skills.

Vocabulary skills of school-age children with acquired brain injury: an exploration of tiered word knowledge and naming errors

BACKGROUND

Vocabulary deficits are the most frequently documented communication difficulty following childhood acquired brain injury (ABI). Given the adverse consequences of limited vocabulary on academic success, it is critical to identify the presence and nature of vocabulary impairments to provide effective intervention for children with ABI.

METHOD

Eleven children (7;6-11;11) with moderate/severe ABI (>12 months post-injury) and individually matched typically developing (TD) controls completed an Australian adaptation of a vocabulary assessment based on a three-tiered framework: tier 1 (basic words), tier 2 (high-frequency, cross-curricular words), and tier 3 (curriculum-based words). Overall scores and tiered accuracy were compared at individual and group level. Type and frequency of expressive naming errors were also coded.

RESULTS

In this pilot study, children with ABI demonstrated poorer overall scores than TD children. Equivalent accuracy was noted for tier 1 words and tier 2 receptive words. However, significantly poorer accuracy was noted in the ABI group for tier 2 expressive words and all tier 3 words. The majority of naming errors were semantic across both groups although TD participants showed a wider distribution of error types.

CONCLUSIONS

Findings support the use of tier 2 and 3 vocabulary as intervention targets in this population within education contexts and speech pathology settings.

The impact of language co-activation on L1 and L2 speech fluency

Fluent speech depends on the availability of well-established linguistic knowledge and routines for speech planning and articulation. A lack of speech fluency in late second-language (L2) learners may point to a deficiency of these representations, due to incomplete acquisition. Experiments on bilingual language processing have shown, however, that there are strong reasons to believe that multilingual speakers experience co-activation of the languages they speak. We have studied to what degree language co-activation affects fluency in the speech of bilinguals, comparing a monolingual German control group with two bilingual groups: 1) first-language (L1) attriters, who have fully acquired German before emigrating to an L2 English environment, and 2) immersed L2 learners of German (L1: English). We have analysed the temporal fluency and the incidence of disfluency markers (pauses, repetitions and self-corrections) in spontaneous film retellings. Our findings show that learners to speak more slowly than controls and attriters. Also, on each count, the speech of at least one of the bilingual groups contains more disfluency markers than the retellings of the control group. Generally speaking, both bilingual groups-learners and attriters-are equally (dis)fluent and significantly more disfluent than the monolingual speakers. Given that the L1 attriters are unaffected by incomplete acquisition, we interpret these findings as evidence for language competition during speech production.

Studying the mechanisms of language learning by varying the learning environment and the learner

Language learning is a resilient process, and many linguistic properties can be developed under a wide range of learning environments and learners. The first goal of this review is to describe properties of language that can be developed without exposure to a language model - the resilient properties of language - and to explore conditions under which more fragile properties emerge. But even if a linguistic property is resilient, the developmental course that the property follows is likely to vary as a function of learning environment and learner, that is, there are likely to be individual differences in the learning trajectories children follow. The second goal is to consider how the resilient properties are brought to bear on language learning when a child is exposed to a language model. The review ends by considering the implications of both sets of findings for mechanisms, focusing on the role that the body and linguistic input play in language learning.

Gesturing with an injured brain: how gesture helps children with early brain injury learn linguistic constructions

Children with pre/perinatal unilateral brain lesions (PL) show remarkable plasticity for language development. Is this plasticity characterized by the same developmental trajectory that characterizes typically developing (TD) children, with gesture leading the way into speech? We explored this question, comparing eleven children with PL - matched to thirty TD children on expressive vocabulary - in the second year of life. Children with PL showed similarities to TD children for simple but not complex sentence types. Children with PL produced simple sentences across gesture and speech several months before producing them entirely in speech, exhibiting parallel delays in both gesture + speech and speech-alone. However, unlike TD children, children with PL produced complex sentence types first in speech-alone. Overall, the gesture-speech system appears to be a robust feature of language learning for simple - but not complex - sentence constructions, acting as a harbinger of change in language development even when that language is developing in an injured brain.

Exploring the relationship between word processing and verbal short-term memory: evidence from associations and dissociations

A theory of the cognitive organisation of lexical processing, verbal short-term memory, and verbal learning is presented along with a summary of data that bear on this issue. We conceive of verbal STM as the outcome of processing that invokes both a specialised short-term memory and the lexical system. On this model, performance of verbal STM tasks depends on the integrity of lexical knowledge, access to that knowledge, and processes that encode serial order information.

Effect of intracranial bleeds on the neurocognitive, academic, behavioural and adaptive functioning of boys with haemophilia

Brain insults are a risk factor for neuropsychological and academic deficits across several paediatric conditions. However, little is known about the specific effects of intracranial haemorrhage (ICH) in boys with haemophilia. The study compared neurocognitive, academic and socio-emotional/behavioural outcomes of boys with haemophilia with and without a history of ICH. Of 172 consecutive patients seen at a Pediatric Comprehensive Care Hemophila Centre, 18 had a history of ICH. Sixteen boys between the ages of 3 and 17 years were available for study and were matched to controls with haemophilia of the same age and disease severity and on the basis of maternal education. Groups were compared on neuropsychological and academic outcomes. Attention, socio-emotional function and executive skills were compared using data from parent questionnaires. Differences were found in intellectual function, visual-spatial skill, fine motor dexterity and particularly language-related skills, including vocabulary, word reading and applied math problem solving. Despite these group differences, outcomes were within the average range for most boys with ICH. No group differences were found in behavioural and socio-emotional functioning. Although ICH in haemophilia is not benign, it was not associated with significant cognitive and academic consequences for most boys. Early neuropsychological assessment may be indicated when there is a history of ICH. Investigation of age at ICH and quantitative measures of brain in relation to neurocognitive outcomes in larger groups of boys with ICH would be useful.

Narrative skill in children with early unilateral brain injury: a possible limit to functional plasticity

Children with pre- or perinatal brain injury (PL) exhibit marked plasticity for language learning. Previous work has focused mostly on the emergence of earlier-developing skills, such as vocabulary and syntax. Here we ask whether this plasticity for earlier-developing aspects of language extends to more complex, later-developing language functions by examining the narrative production of children with PL. Using an elicitation technique that involves asking children to create stories de novo in response to a story stem, we collected narratives from 11 children with PL and 20 typically developing (TD) children. Narratives were analysed for length, diversity of the vocabulary used, use of complex syntax, complexity of the macro-level narrative structure and use of narrative evaluation. Children's language performance on vocabulary and syntax tasks outside the narrative context was also measured. Findings show that children with PL produced shorter stories, used less diverse vocabulary, produced structurally less complex stories at the macro-level, and made fewer inferences regarding the cognitive states of the story characters. These differences in the narrative task emerged even though children with PL did not differ from TD children on vocabulary and syntax tasks outside the narrative context. Thus, findings suggest that there may be limitations to the plasticity for language functions displayed by children with PL, and that these limitations may be most apparent in complex, decontextualized language tasks such as narrative production.

Does linguistic input play the same role in language learning for children with and without early brain injury?

Children with unilateral pre- or perinatal brain injury (BI) show remarkable plasticity for language learning. Previous work highlights the important role that lesion characteristics play in explaining individual variation in plasticity in the language development of children with BI. The current study examines whether the linguistic input that children with BI receive from their caregivers also contributes to this early plasticity, and whether linguistic input plays a similar role in children with BI as it does in typically developing (TD) children. Growth in vocabulary and syntactic production is modeled for 80 children (53 TD, 27 BI) between 14 and 46 months. Findings indicate that caregiver input is an equally potent predictor of vocabulary growth in children with BI and in TD children. In contrast, input is a more potent predictor of syntactic growth for children with BI than for TD children. Controlling for input, lesion characteristics (lesion size, type, seizure history) also affect the language trajectories of children with BI. Thus, findings illustrate how both variability in the environment (linguistic input) and variability in the organism (lesion characteristics) work together to contribute to plasticity in language learning.

Language outcome after perinatal stroke: does side matter?

The goal of this study was to examine structured language skills in children with perinatal strokes. Participants were 28 school-age children with early focal brain lesions (17 with left hemisphere [LH] damage, 11 with right hemisphere [RH] damage), and 57 controls. A standardized test of language (Clinical Evaluation of Language Fundamentals-Revised) was administered. Receptive, Expressive, and Total Language scores, as well as subtest scores, were analyzed. Control participants scored within the normal range, whereas the LH and RH groups scored significantly more poorly than did controls. There were no differences between the LH and RH groups on any of the language scores, and all scores were below the 14th percentile. Within the lesion group as a whole, scores were not related to lesion laterality, site, or severity. Results also were not accounted for by socioeconomic status or IQ. However, children who experienced seizures demonstrated significantly poorer performance than did children who did not experience seizures. Damage to either the LH or RH early in development adversely affects later language abilities, particularly on tasks with structured and complex linguistic demands. Although lesion side has little effect, the presence or absence of seizures is a major contributor to language outcome.

Dynamic self-organization and early lexical development in children

In this study we present a self-organizing connectionist model of early lexical development. We call this model DevLex-II, based on the earlier DevLex model. DevLex-II can simulate a variety of empirical patterns in children's acquisition of words. These include a clear vocabulary spurt, effects of word frequency and length on age of acquisition, and individual differences as a function of phonological short-term memory and associative capacity. Further results from lesioned models indicate developmental plasticity in the network's recovery from damage, in a non-monotonic fashion. We attribute the network's abilities in accounting for lexical development to interactive dynamics in the learning process. In particular, variations displayed by the model in the rate and size of early vocabulary development are modulated by (a) input characteristics, such as word frequency and word length, (b) consolidation of lexical-semantic representation, meaning-form association, and phonological short-term memory, and (c) delayed processes due to interactions among timing, severity, and recoverability of lesion. Together, DevLex and DevLex-II provide an accurate computational account of early lexical development.

Using the language characteristics of clinical populations to understand normal language development

The overall purpose of this article is to describe the speech and language abilities of children who have selected clinical conditions, not only to characterize the outcomes of those conditions, but also to understand fundamental requirements for language learning in typically developing children. This developmental cognitive neuroscience analysis conceptualizes the clinical conditions as naturalistic experimental manipulations, selectively altering factors in the language-learning situation that could not otherwise be ethically manipulated in a research study.

Nonword repetition and sentence repetition as clinical markers of specific language impairment: the case of Cantonese

PURPOSE

Recent research suggests that nonword repetition (NWR) and sentence repetition (SR) tasks can be used to discriminate between children with SLI and their typically developing age-matched (TDAM) and younger (TDY) peers.

METHOD

Fourteen Cantonese-speaking children with SLI and 30 of their TDAM and TDY peers were compared on NWR and SR tasks. NWR of IN nonwords (CV combinations attested in the language) and OUT nonwords (CV combinations unattested in the language) were compared. SR performance was compared using 4 different scoring methods.

RESULTS

The SLI group did not score significantly lower than the TDAM group on the test of NWR (overall results were TDAM = SLI > TDY). There were nonsignificant group differences on IN syllables but not on OUT syllables. The results do not suggest a limitation in phonological working memory in Cantonese-speaking children with SLI. The SR task discriminated between children and their TDAM peers but not between children with SLI and their TDY peers matched for mean length of utterance.

CONCLUSIONS

SR but not NWR discriminates between children with SLI and their TDAM peers. Poorer NWR for English-speaking children with SLI might be attributable to weaker use of the redintegration strategy in word repetition. Further cross-linguistic investigations of processing strategies are required.

Model based prognosis of postoperative object naming in left temporal lobe epilepsy

Epilepsy surgery in the left temporal lobe is associated with a high risk of naming decline. In the present study, in 45 patients with left temporal lobe epilepsy (TLE) and confirmed left hemisphere language dominance, 13 (29%) patients demonstrated postoperative decrement >or=5 naming failures in the Boston Naming Test (BNT). Multivariate discriminant analysis with age at onset of epilepsy, age at first risk, age at operation and preoperative naming performance as predictors indicated that 12 (92%) patients with later naming decline could be identified preoperatively. Univariate group comparisons revealed that specifically patients with seizure onset later than 14 years without preceding risk factors (e.g., febrile seizures) are in danger of postoperative dysnomia. It is hypothesized, that there is a strong connection between stable naming performance and deviant intrahemispheric speech representation as a result of early brain damage and/or chronic seizures.

Parallel FoxP1 and FoxP2 expression in songbird and human brain predicts functional interaction

Humans and songbirds are two of the rare animal groups that modify their innate vocalizations. The identification of FOXP2 as the monogenetic locus of a human speech disorder exhibited by members of the family referred to as KE enables the first examination of whether molecular mechanisms for vocal learning are shared between humans and songbirds. Here, in situ hybridization analyses for FoxP1 and FoxP2 in a songbird reveal a corticostriatal expression pattern congruent with the abnormalities in brain structures of affected KE family members. The overlap in FoxP1 and FoxP2 expression observed in the songbird suggests that combinatorial regulation by these molecules during neural development and within vocal control structures may occur. In support of this idea, we find that FOXP1 and FOXP2 expression patterns in human fetal brain are strikingly similar to those in the songbird, including localization to subcortical structures that function in sensorimotor integration and the control of skilled, coordinated movement. The specific colocalization of FoxP1 and FoxP2 found in several structures in the bird and human brain predicts that mutations in FOXP1 could also be related to speech disorders.

Phonological memory and vocabulary learning in children with focal lesions

Eleven children with early focal lesions were compared with 70 age-matched controls to assess their performance in repeating non-words, in learning new words, and in immediate serial recall, a triad of abilities that are believed to share a dependence on serial ordering mechanisms (e.g.,; ). Results for the experimental group were also compared with other assessments previously reported for the same children by. The children with brain injury showed substantial impairment relative to controls in the experimental tasks, in contrast with relatively unimpaired performance on measures of vocabulary and non-verbal intelligence. The relationships between word learning, non-word repetition, and immediate serial recall were similar to those observed in several other populations. These results support previous reports that there are persistent processing impairments following early brain injury, despite developmental plasticity. They also suggest that word learning, non-word repetition, and immediate serial recall may be relatively demanding tasks, and that their relationship is a fundamental aspect of the cognitive system.

Discourse plasticity in children after stroke: age at injury and lesion effects

Studies of children with stroke indicate remarkable recovery of language after some initial delay. However, complex language abilities as measured by discourse (connected language) may be required to detect the full impact of stroke on subsequent cognitive-linguistic development. This study examined discourse ability in children with stroke as compared with orthopedic controls, age-at-injury, and lesion effects. Discourse between two groups of children was compared [stroke (n = 17) vs orthopedic control (n = 17)]. The stroke group was subdivided into early age at stroke (<1 year) and late age at stroke (>1 year). The discourse samples were analyzed along two dimensions: language and information structure. Results revealed that the stroke group performed at significantly lower levels than the orthopedic control group across discourse measures. The most important finding was a poorer outcome for early age at stroke as compared with later age at stroke. These findings alter the widespread belief of optimistic language outcomes after childhood stroke. Interestingly, no site or size-of-lesion effects, common to adult stroke, were identified. These findings identify poor long-term outcome with early brain insults at stages far removed from the onset of injury. The implication is that childhood stroke management should be revised to provide protracted follow-up and treatment.

Bilateral brain abnormalities associated with dominantly inherited verbal and orofacial dyspraxia

The KE family is a large three-generational pedigree in which half of the members suffer from a verbal and orofacial dyspraxia in association with a point mutation in the FOXP2 gene. This report extends previous voxel-based morphometric analyses of magnetic resonance imaging (MRI) scans (Watkins et al. [2002] Brain 125:465-478) using a bilateral conjunction analysis. This searches specifically for areas of grey matter density that differ bilaterally in the affected members compared with both matched controls and the unaffected family members. 3-D T1-weighted MRI datasets of 17 family members (10 affected, 7 unaffected) and matched controls were compared. The most significant findings were reduced grey matter density bilaterally in the caudate nucleus, the cerebellum, and the left and right inferior frontal gyrus in the affected members. In addition, increased grey matter density was found bilaterally in the planum temporale. These results confirm that a point mutation in FOXP2 is associated with several bilateral grey matter abnormalities in both motor and language related regions. The results also demonstrate the advantages of using a conjunction analysis when bilateral abnormalities are suspected.

Examination of sensorimotor performance following middle cerebral artery occlusion in rats

Middle cerebral artery occlusion (MCAO) in rats is the most commonly used stroke model. Besides the infarct size, assessment of sensorimotor performance has become increasingly important in neuroprotective drug research. However, contradictions exist about procedures for testing functional outcome following MCAO. The aim of the present study was to evaluate a relatively simple set of neurological tests based on the most commonly used scoring systems, and to describe the functional recovery and correlation with the infarct size in rats sacrificed 2 or 14 days after permanent or transient MCAO. The smaller infarct size of rats with transient occlusion was reflected in the neurological scores only during the first 6h. By day 14, no recovery occurred in postural signs, lateral resistance and spontaneous activity, other signs showed different degrees of recovery. Correlation with the infarct size was found only on certain days in gait disturbance, placing reactions, daily body weight and spontaneous activity. According to our observations, the most commonly used sensorimotor tests provide a useful initial screening of functional deficits, but these tests most probably measure deficits caused by infarction of the core area. It is suggested that these tests should be completed by more refined tests when testing a neuroprotective drug which reduces the infarct size in penumbral areas.