Building a unified model of the Optional Infinitive Stage: simulating the cross-linguistic pattern of verb-marking error in typically developing children and children with Developmental Language Disorder

Verb-marking errors are a characteristic feature of the speech of typically-developing (TD) children and are particularly prevalent in the speech of children with Developmental Language Disorder (DLD). However, both the pattern of verb-marking error in TD children and the pattern of verb-marking deficit in DLD vary across languages and interact with the semantic and syntactic properties of the language being learned. In this paper, we review work using a computational model called MOSAIC. We show how this work allows us to understand several features of the cross-linguistic data that are otherwise difficult to explain. We also show how discrepancies between the developmental data and the quantitative predictions generated by MOSAIC can be used to identify weaknesses in our current understanding and lead to further theory development; and how the resulting model (MOSAIC+) helps us understand differences in the cross-linguistic patterning of verb-marking errors in TD children and children with DLD

Persistent emotional disorder in children with neurological soft signs

Provides clinical details in the form of 11 case vignettes from a prospective epidemiological study that found the combination of childhood \u27soft\u27 signs and anxious behavior to be a strong risk factor for adolescent emotional disorders. The original study conducted a neuropsychiatric assessment of 180 African-American adolescents (aged 16–18 yrs) who had been followed through childhood. The at-risk Ss exhibited a persistent and specific pattern of both motor abnormalities and anxiety, obsessional compulsive, or depressive symptoms over time. The form of at-risk Ss\u27 neurological and psychiatric abnormalities is consistent with a link between motor system abnormalities and emotional disorders

Modelling Children's Sentence Recall using an Encoder-Decoder Network

Elicited imitation is a widely used method for testing a child's knowledge of a language for scientific or clinical purposes. A child hears an utterance and is asked to repeat what they have heard. While it is assumed that their fluency or speed in doing so is contingent on their linguistic competence, little is known about the cognitive mechanisms and/or representations involved. To explore this, we train an encoder-decoder model, consisting of recurrent neural networks, to encode and reproduce a corpus of child-directed speech and then test its performance on the experimental task of Bannard and Matthews (2008). In that study pre-school children were asked to repeat high- and low-frequency four-word sequences in which the first three words were identical (e.g., sit in your chair and sit in your truck) and the final words and bigrams were closely matched for frequency. We find that like those children our model makes more errors on the initial three words when they are part of a low-frequency than a high-frequency sequence, despite the fact that the words being repeated are identical. We explore why this might be and pinpoint some possible similarities between the model and child language processing

An extremely rich repertoire of bursting patterns during the development of cortical cultures

BACKGROUND: We have collected a comprehensive set of multi-unit data on dissociated cortical cultures. Previous studies of the development of the electrical activity of dissociated cultures of cortical neurons each focused on limited aspects of its dynamics, and were often based on small numbers of observed cultures. We followed 58 cultures of different densities – 3000 to 50,000 neurons on areas of 30 to 75 mm(2 )– growing on multi-electrode arrays (MEAs) during the first five weeks of their development. RESULTS: Plating density had a profound effect on development. While the aggregate spike detection rate scaled linearly with density, as expected from the number of cells in proximity to electrodes, dense cultures started to exhibit bursting behavior earlier in development than sparser cultures. Analysis of responses to electrical stimulation suggests that axonal outgrowth likewise occurred faster in dense cultures. After two weeks, the network activity was dominated by population bursts in most cultures. In contrast to previous reports, development continued with changing burst patterns throughout the observation period. Burst patterns were extremely varied, with inter-burst intervals between 1 and 300 s, different amounts of temporal clustering of bursts, and different firing rate profiles during bursts. During certain stages of development bursts were organized into tight clusters with highly conserved internal structure. CONCLUSION: Dissociated cultures of cortical cells exhibited a much richer repertoire of activity patterns than previously reported. Except for the very sparsest cultures, all cultures exhibited globally synchronized bursts, but bursting patterns changed over the course of development, and varied considerably between preparations. This emphasizes the importance of using multiple preparations – not just multiple cultures from one preparation – in any study involving neuronal cultures. These results are based on 963 half-hour-long recordings. To encourage further investigation of the rich range of behaviors exhibited by cortical cells in vitro, we are making the data available to other researchers, together with Matlab code to facilitate access

Minor physical anomalies: Modifiers of environmental risk for psychopathology

Tested the hypothesis that minor physical anomalies (MPAs) modify an adolescent\u27s vulnerability to environmental risk factors for psychopathology. 118 male 17-yr-olds who had been evaluated as 7-year-olds received a comprehensive neuropsychiatric evaluation. The evaluation included standardized assessments of environmental risk factors for psychiatric impairment, neurological signs, IQ, MPAs, and psychiatric impairment. The relationship between psychiatric status and environmental risk was examined as a function of the MPA profile. There was a significant interaction between MPAs and environmental risk in predicting psychiatric status. Environmental risk was more predictive of psychiatric impairment at age 17 in Ss with high scores on the MPA scale than in Ss with low scores on the scale. This relationship was particularly apparent in Ss with conduct disorder. MPAs also exhibited relationships with 2 childhood factors, neurological soft signs and Verbal IQ, that had been shown to predict adolescent psychopathology in prior reports on this cohort

Attention bias and anxiety in young children exposed to family violence

Background—Attention bias towards threat is associated with anxiety in older youth and adults and has been linked with violence exposure. Attention bias may moderate the relationship between violence exposure and anxiety in young children. Capitalizing on measurement advances, the current study examines these relationships at a younger age than previously possible. Methods—Young children (mean age 4.7, ±0.8) from a cross-sectional sample oversampled for violence exposure (N = 218) completed the dot-probe task to assess their attention biases. Observed fear/anxiety was characterized with a novel observational paradigm, the Anxiety Diagnostic Observation Schedule. Mother-reported symptoms were assessed with the Preschool-Age Psychiatric Assessment and Trauma Symptom Checklist for Young Children. Violence exposure was characterized with dimensional scores reflecting probability of membership in two classes derived via latent class analysis from the Conflict Tactics Scales: Abuse and Harsh Parenting. Results—Family violence predicted greater child anxiety and trauma symptoms. Attention bias moderated the relationship between violence and anxiety

Cortical and subcortical brain structure in generalized anxiety disorder : findings from 28 research sites in the ENIGMA-Anxiety Working Group

The goal of this study was to compare brain structure between individuals with generalized anxiety disorder (GAD) and healthy controls. Previous studies have generated inconsistent findings, possibly due to small sample sizes, or clinical/analytic heterogeneity. To address these concerns, we combined data from 28 research sites worldwide through the ENIGMA-Anxiety Working Group, using a single, pre-registered mega-analysis. Structural magnetic resonance imaging data from children and adults (5–90 years) were processed using FreeSurfer. The main analysis included the regional and vertex-wise cortical thickness, cortical surface area, and subcortical volume as dependent variables, and GAD, age, age-squared, sex, and their interactions as independent variables. Nuisance variables included IQ, years of education, medication use, comorbidities, and global brain measures. The main analysis (1020 individuals with GAD and 2999 healthy controls) included random slopes per site and random intercepts per scanner. A secondary analysis (1112 individuals with GAD and 3282 healthy controls) included fixed slopes and random intercepts per scanner with the same variables. The main analysis showed no effect of GAD on brain structure, nor interactions involving GAD, age, or sex. The secondary analysis showed increased volume in the right ventral diencephalon in male individuals with GAD compared to male healthy controls, whereas female individuals with GAD did not differ from female healthy controls. This megaanalysis combining worldwide data showed that differences in brain structure related to GAD are small, possibly reflecting heterogeneity or those structural alterations are not a major component of its pathophysiology

Grey matter volume in adolescent anxiety: an impact of the Brain-derived neurotropic factor Val66Met polymorphism?

Objective: Minimal research links anxiety disorders in adolescents to regional gray matter volume (GMV) abnormalities and their modulation by genetic factors. Prior research suggests that a brain-derived neurotrophic factor (BNDF) Val(66)Met polymorphism may modulate such brain morphometry profiles. Method: Using voxel-based morphometry and magnetic resonance imaging, associations of BDNF and clinical anxiety with regional GMVs of anterior cingulate cortex, insula, amygdala, and hippocampus were examined in 39 affected (17 Met allele carriers, 22 Val/Val homozygotes) and 63 nonaffected adolescents (33 Met allele carriers, 41 Val/Val homozygotes). Results: Amygdala and anterior hippocampal GMVs were significantly smaller in patients than in healthy comparison adolescents, with a reverse pattern for the insula. Post-hoc regression analyses indicated a specific contribution of social phobia to the GMV reductions in the amygdala and hippocampus. In addition, insula and dorsal anterior cingulate cortex (ACC) GMVs were modulated by BDNF genotype. In both regions, and GMVs were larger in the Val/Val homozygote patients than in individuals carrying the Met allele. Conclusions: These results implicate reduced GMV in the amygdala and hippocampus in pediatric anxiety, particularly social phobia. In addition, the data suggest that genetic factors may modulate differences in the insula and dorsal ACC. J. Am. Acad. Child Adolesc. Psychiatry; 2013;52(2):184-195

Age-Related Influence of Contingencies on a Saccade Task

Background: Adolescence is characterized by increased risk-taking and sensation seeking, presumably brought about by developmental changes within reward-mediating brain circuits. A better understanding of the neural mechanisms underlying reward-seeking during adolescence can have critical implications for the development of strategies to enhance adolescent performance in potentially dangerous situations. Yet little research has investigated the influence of age on the modulation of behavior by incentives with neuroscience-based methods Methods: A monetary reward antisaccade task (the RST) was used with 23 healthy adolescents and 30 healthy adults. Performance accuracy, latency and peak velocity of saccade responses (prosaccades and antisaccades) were analyzed. Results: Performance accuracy across all groups was improved by incentives (obtain reward, avoid punishment) for both, prosaccades and antisaccades. However, modulation of antisaccade errors (direction errors) by incentives differed between groups: adolescents modulated saccade latency and peak velocity depending on contingencies, with incentives aligning their performance to that of adults; adults did not show a modulation by incentives. Conclusions: These findings suggest that incentives modulate a global measure of performance (percent direction errors) in adults and adolescents, and exert a more powerful influence on the control of incorrect motor responses in adolescents than in adults. These findings suggest that this task can be used in neuroimaging studies as a probe of the influence of incentives on cognitive control from a developmental perspective as well as in health and disease