Mental number line training in children with developmental dyscalculia.

Developmental dyscalculia (DD) is a specific learning disability that affects the acquisition of mathematical skills in children with normal intelligence and age-appropriate school education (prevalence 3-6%). One essential step in the development of mathematical understanding is the formation and automated access to a spatial representation of numbers. Many children with DD show a deficient development of such a mental number line. The present study aimed to develop a computer-based training program to improve the construction and access to the mental number line. Sixteen children with DD aged 8-10 years and 16 matched control children completed the 5-week computer training. All children played the game 15 min a day for 5 days a week. The efficiency of the training was evaluated by means of neuropsychological tests and functional magnetic resonance imaging (fMRI) during a number line task. In general, children with and without DD showed a benefit from the training indicated by (a) improved spatial representation of numbers and (b) the number of correctly solved arithmetical problems. Regarding group differences in brain activation, children with DD showed less activation in bilateral parietal regions, which reflects neuronal dysfunction in pivotal regions for number processing. Both groups showed reduced recruitment of relevant brain regions for number processing after the training which can be attributed to automatization of cognitive processes necessary for mathematical reasoning. Moreover, results point to a partial remediation of deficient brain activation in dyscalculics after consolidation of acquired and refined number representation. To conclude, the present study represents the first attempt to evaluate a custom-designed training program in a group of dyscalculic children and results indicate that the training leads to an improved spatial representation of the mental number line and a modulation of neural activation, which both facilitate processing of numerical tasks.

Dysfunctional neural network of spatial working memory contributes to developmental dyscalculia.

The underlying neural mechanisms of developmental dyscalculia (DD) are still far from being clearly understood. Even the behavioral processes that generate or influence this heterogeneous disorder are a matter of controversy. To date, the few studies examining functional brain activation in children with DD mainly focus on number and counting related tasks, whereas studies on more general cognitive domains that are involved in arithmetical development, such as working memory are virtually absent. There are several studies showing a close relationship between DD and spatial working memory [Camos, V. (2008). Low working memory capacity impedes both efficiency and learning of number transcoding in children. Journal of Experimental Child Psychology, 99(1), 37-57; McLean, J. F., & Hitch, G. J. (1999). Working memory impairments in children with specific arithmetic learning difficulties. Journal of Experimental Child Psychology, 74(3), 240-260; Rosselli, M., Matute, E., Pinto, N., & Ardila, A. (2006). Memory abilities in children with subtypes of dyscalculia. Developmental Neuropsychology, 30(3), 801-818; Siegel, L. S., & Ryan, E. B. (1989). The development of working memory in normally achieving and subtypes of learning disabled children. Child Development, 60(4), 973-980]. The relationship between these two mechanisms is still matter of debate, but this study follows the assumption that poor spatial working memory capacity may hinder the acquisition of spatial number representations in children with DD [Geary, D. C. (1993). Mathematical disabilities: Cognitive, neuropsychological, and genetic components. Psychological Bulletin, 114(2), 345-362; von Aster, M., & Shalev, R. S. (2007). Number development and developmental dyscalculia. Developmental Medicine and Child Neurology, 49(11), 868-873]. Using functional MRI the current study compares brain activity associated with spatial working memory processes in 8-10-year-old children with DD and normally achieving controls. Both groups showed significant spatial working memory related activity in a network including occipital and parietal regions. Children with DD showed weaker neural activation compared to the control group during a spatial working memory task in the right intraparietal sulcus (IPS), the right insula and the right inferior frontal lobe. Performance tests outside the scanner showed impaired working memory proficiency in children with DD. Bringing behavioral performance and neural activity together we found significant correlations of right IPS activity with performance on the verbal digit span forward and the spatial Corsi Block Tapping test. Our findings demonstrate for the first time an involvement of spatial working memory processes in the neural underpinnings of DD. These poor spatial working memory processes may inhibit the formation of spatial number representations (mental numberline) as well as the storage and retrieval of arithmetical facts.

Optimized voxel-based morphometry in children with developmental dyscalculia.

Developmental dyscalculia (DD) is a specific learning disability affecting the normal acquisition of arithmetic skills. Current studies estimate that 3-6% of the school population is affected by DD. Genetic, neurobiological, and epidemiologic evidence indicates that dyscalculia is a brain-based disorder. Imaging studies suggest the involvement of parietal and prefrontal cortices in arithmetic tasks. The aim of the present study was to analyze if children with DD show structural differences in parietal, frontal, and cingulate areas compared to typically achieving children. Magnetic resonance imaging was obtained from 12 children with DD aged 9.3+/-0.2 years and 12 age-matched control children without any learning disabilities on a 1.5 T whole-body scanner. Voxel-based morphometry analysis with an optimization of spatial segmentation and normalization procedures was applied to compare the two groups in order to find differences in cerebral gray and white matter. Compared to controls, children with DD show significantly reduced gray matter volume in the right intraparietal sulcus (IPS), the anterior cingulum, the left inferior frontal gyrus, and the bilateral middle frontal gyri. White matter comparison demonstrates clusters with significantly less volume in the left frontal lobe and in the right parahippocampal gyrus in dyscalculic children. The decreased gray and white matter volumes in the frontoparietal network might be the neurological substrate of impaired arithmetic processing skills. The white matter volume decrease in parahippocampal areas may have influence on fact retrieval and spatial memory processing.

Brain activation during mental rotation in school children and adults.

Mental rotation is a complex cognitive skill depending on the manipulation of mental representations. We aimed to investigate the maturing neuronal network for mental rotation by measuring brain activation in 20 children and 20 adults using functional magnetic resonance imaging. Our results indicate that brain activation patterns are very similar between children and adults. However, adults exhibit stronger activation in the left intraparietal sulcus compared to children. This finding suggests a shift of activation from a predominantly right parietal activation in children to a bilateral activation pattern in adults. Furthermore, adults show a deactivation of the posterior cingulate gyrus and precuneus, which is not observed in children. In conclusion, developmental changes of brain activation during mental rotation are leading to a bilateral parietal activation pattern and faster performance.

Number processing and mental calculation in school children aged 7 to 10 years: a transcultural comparison.

Neuropsychological studies of dyscalculic patients show that arithmetical development is not a unidimensional process. In transcultural investigations, cultural, educational and linguistic factors might affect differently the various components of mathematical development. Four hundred and sixty schoolchildren aged 7 to 10 years from Brasilia, Brazil (n = 141), Paris, France (n = 160) and Zurich, Switzerland (n = 159) were asked to perform eleven number processing and calculation tasks. Chronological age, which was almost confounded in this study to educational level, had a strong effect on some tasks (knowledge of the written code of numbers, number comparison, mental calculation, problem solving), but only a slight effect on other tasks (counting dots, counting backwards, estimation). Also, linguistic factors and factors related to the socio-economic level of the family had different effects on the various components of calculation and number processing. Evidence from developmental studies has to be integrated into theoretical models of calculation and number processsing, which are presently based mainly on results from neuropsychological studies of dyscalculic patients.

Developmental cognitive neuropsychology of number processing and calculation: varieties of developmental dyscalculia.

This article provides a brief overview about the current state of cognitive developmental neuropsychology of developmental dyscalculia (DD) as well as results from a Zurich study that investigates different subtypes of DD according to various aspects of numerical abilities that are impaired or preserved. The differential effects of impairments of one particular numerical area on the development of other numerical abilities are highlighted in the case of a 17 year old boy with severe DD and Developmental Gerstmann Syndrome. A comprehensive model of developmental dynamics of number processing and calculation abilities will be proposed in the last section with respect to the development of intelligence theory.

[Child and adolescent psychiatric services in the canton of Zurich: a comparison of outpatients, day clinic, and inpatient referral populations]. / Kinder- und jugendpsychiatrische Versorgung im Kanton Zürich: Vergleich der Inanspruchnahme von Ambulanz, Tagesklinik und Station.

Findings in intervention research are an important basis for the discussion of issues pertaining to quality control. In Switzerland such findings have been rare. The present study of the entire 1988-1995 referred child and adolescent population of the Child and Adolescent Psychiatric Service of the Canton of Zurich (N = 7538 treated patients) concentrated on the demographic, diagnostic, and therapeutic attributes of the outpatient, day clinic, and inpatient populations that comprised the referred population. Marked differences are found in comparable studies from Germany with regard to patients treated in an inpatient setting. For example, the mean age of the patients in the Zurich sample is lower and patients with conduct disorders are more frequently represented. On the other hand, patients with psychotic illness are missing and, on the average, the duration of treatment is considerably longer. The reasons for these differences are to be found in the various structural attributes of the cantonal services that are provided in Zurich. In the area of inpatient care, where in comparison to outpatient settings and also day care settings patients with severe disorders are treated, there is a lack of places for the short-term care of acutely ill patients--for example, psychotic patients. This is especially true for adolescent patients. The limitations of traditional outpatient settings are frequently marked by unsatisfactory treatment results in outpatients with conduct disorders, developmental disorders, and a high impact of abnormal psychosocial circumstances.

Psychiatric, neuropediatric, and neuropsychological symptoms in a case of hypomelanosis of Ito.

This case report presents a thirteen year-old boy who was diagnosed as having Hypomelanosis of Ito. The developmental history includes severe failure to thrive, and moderate atypical autism as well as diverse clinical and neuropsychological symptoms are present. The pattern of neuropsychological functioning, which can be partially related to the neurophysiological findings, is discussed within the context of existing neuropsychological theories about autistic disorders.

[Documentation of psychopathologic findings: a procedure for the evaluation of psychological disorders in children and adolescents]. / Die Psychopathologische Befund-Dokumentation: Ein Verfahren zur Beurteiling psychischer Störungen bei Kindern und Jugendlichen.

A standardized documentation system for psychopathological findings allowing an assessment of psychiatric disorders in children and adolescents after clinical evaluation of the patient and his or her caregivers is presented. The symptomatology during the previous few months and the symptoms seen during the examination are rated separately. Altogether 113 items in 16 areas are assessed. In addition, motivation to participate in treatment is judged and a global assessment is made of symptom severity. A number of facilities are already employing this documentation system in their routine clinical work. In a first study 597 patients from a routine clinical population seen consecutively were assessed at the start of treatment. As expected, the most commonly recorded symptoms were those of expansive behavior. Such symptoms were seen much more rarely during the evaluation than outside this situation. The documentation system for psychopathological findings complements diagnosis by category according to ICD with a phenomenological description of psychiatric disturbances on the level of single symptoms. It enables simple and economical documentation of clinical findings after evaluation of the patient and his or her caregivers.

[Children with a specific weakness in mathematics in a referred population]. / Kinder mit umschriebener Rechenschwäche in einer Inanspruchnahmepopulation.

In the present study children with dycalculia were described and compared with children with specific reading and spelling disabilities and children without clinical diagnosis. All children were referred to a child psychiatric outpatient and inpatient department. The comparison was carried out over clinical data drawn from the general data documentation and from written case reports including diagnostical, anamnestical, symptomatological and developmental neurological data. More than 50% of the dyscalculic children displayed other child psychiatric disorders, especially emotional disorders. It is questioned in the light of developmental psychological understanding if the developmental neurological deficits of the dyscalculic children can be seen as etiological significant in the sense of basical disorders concerning the deficient development of stable conceptions of an inner number space.

Comparative studies of conversion disorders in childhood and adolescence.

In a syndrome validation study, four groups of patients suffering from conversion disorders, anxiety states, obsessive-compulsive disorder and emotional disorders, as well as a healthy control group, were compared. The following findings emerged: besides female preponderance and greater age, a higher rate of low SES subjects and social migration patients suffering from conversion disorders displayed a greater proportion of psychiatric and medical diseases in their parental heritage.

[Behavior therapy in use--assessment of 633 cases of treatment]. / Verhaltenstherapie in der Anwendung--Auswertung von 633 Behandlungen.

633 written case-reports of behavior therapies were statistically evaluated. The case-reports, provided by 180 behavior therapists, were presented to the Deutsche Gesellschaft für Verhaltenstherapie in concurrence with their behavior therapy training closing criteria. Data concerning therapists and institutional settings were taken into consideration as well as data about patients, their disorders, specific treatments, lengths of therapy and outcomes. Results were discussed in the light of psychiatric-epidemiological and psychotherapy research as well as the general trends in theory and practice of psychotherapy.

[Functional hemispheric asymmetry in children with hypersynchronous activity in the EEG. A study with the dichotic listening procedure]. / Untersuchungen zur funktionellen Hemisphärenasymmetrie bei Kindern mit hypersynchroner Aktivität im EEG. Eine Untersuchung mit dem Dichotic-Listening-Verfahren.

24 patients of a child psychiatric clinic with focal epileptiform activity located in different brain areas were tested with a dichotic listening procedure to examine functional hemispheric asymmetry. Children with epilepsy were excluded. No differences were found concerning the lateralisation of the examined functions between the clinical groups and a matched-pair non-clinical control group. Clinical groups as well as the control group showed a right-ear-effect (REE), i.e. a superior functioning of the left hemisphere in processing the presented stimuli. However, children with epileptiform discharges in the left hemisphere showed inferior functioning in the dichotic listening test on both ears in contrast to children with bi-hemispheric discharges and the control group. Results were discussed in the theoretical framework of malfunctions of auditory short time memory.

[Functional hemispheric asymmetry in children with hypersynchronous activity in the EEG. A tachistoscopic study using visuolinguistic stimulus material]. / Funktionelle Hemisphärenasymmetrie bei Kindern mit hypersynchroner Aktivität im EEG. Eine tachistoskopische Untersuchung mit visuo-linguistischem Stimulusmaterial.

24 patients of a child psychiatric clinic with focal epileptiform activity located in different brain areas were tested with tachistoscopically presented letter and word stimuli to examine functional hemisphere asymmetry. Children with epilepsy were excluded. No differences were found concerning the lateralisation of the examined functions between the clinical groups and a matched pair nonclinical control group. All children showed an advantage of the left hemisphere in processing the presented visuo-linguistic stimuli. Children with bihemispheric epileptiform discharges showed superior performance on all tasks in contrast to children with left hemispheric discharges and the control group. Results were discussed in the theoretical framework of raised cortical vigilance in these children. Asymmetric hemispheric functions focal epileptiform discharges tachistoscopic study letter/word recognition test.