Attention deficit hyperactivity disorder (ADHD) is characterized by deficient self-regulation, po... more Attention deficit hyperactivity disorder (ADHD) is characterized by deficient self-regulation, poor attentional control, and poor response inhibition. To date, however, the extent to which these deficits affect basic interference control remains a matter of controversy. Secondly, ADHD has been reported to be associated with arithmetic deficits. It remains unclear whether such deficits are a secondary consequence of the above-mentioned characteristics of ADHD or whether basic numerical magnitude representations are also affected. In the present study we attempted to investigate these issues using a basic numerical interference paradigm. Nine- to twelve-year-old children with ADHD-C (attention-deficit hyperactivity-disorder combined type) and control children without ADHD (each n = 16) were presented with two digits of possibly different physical sizes (e.g., 3 7). This numerical Stroop task requires subjects to make a magnitude classification concerning either the physical or the numerical stimulus dimension. The irrelevant dimension can be congruent (same response), incongruent (different response), or neutral (no response association). Children with ADHD-C performed worse than control children in most analyses. The most important finding was a significant interaction of congruity effects with group in the numerical comparison task. Children with ADHD-C tended to show larger congruity and interference effects than controls, and these were not attributable to a speed-accuracy trade-off. The results might reflect differential processing speeds, or a different degree of automatic activation of physical and numerical magnitudes in children with and without ADHD-C. Alternative explanations, such as insufficient inhibition of selective (domain-specific) attention are also discussed.
Dyskalkulie (umschriebene Rechenstörung) wurde bis vor wenigen Jahren noch kaum als Teilleistungs... more Dyskalkulie (umschriebene Rechenstörung) wurde bis vor wenigen Jahren noch kaum als Teilleistungsstörung beschrieben. In den letzten 5 Jahren scheint Dyskalkulie als Störung in Mode zu kommen und Dyskalkulie-Therapie wird verstärkt nachgefragt und angeboten. Im Gegensatz zur Legasthenie ist die Forschung zur Dyskalkulie aber noch sehr jung und der Stand des Wissens verändert sich rasant. In diesem Artikel wird zunächst beschrieben, was wir 2006 über das Syndrom und seine neurokognitiven Grundlagen wissen, wie wir es modelltheoretisch beschreiben können, wie man es diagnostizieren kann und worauf man bei Interventionen achten muss.
Das Hauptziel dieser retrospektiven Studie war die Untersuchung des differentialdiagnostischen Nu... more Das Hauptziel dieser retrospektiven Studie war die Untersuchung des differentialdiagnostischen Nutzens der CERAD neuropsychologischen Testbatterie zur Unterscheidung geriatrischer Patienten mit leichter kognitiver Störung/MCI (n = 345) mit versus ohne depressiver Symptomatik. Alle Analysen wurden doppelt gerechnet (ICD-10-konforme MCI-Definition und amnestische MCI/a-MCI). Die optimalen empirischen Cutoff-Werte und die diagnostische Genauigkeit wurden mittels Receiver Operating Characteristic/ROC-Analysen berechnet. Die Ergebnisse sind abhängig vom verwendeten MCI-Definitionskriterium und bestätigen die differentialdiagnostische Nützlichkeit der CERAD, allerdings ausschließlich bei Verwendung ICD-10-konformer Definitionskriterien (nicht bei a-MCI). Der CERAD-Summenwert differenziert signifikant zwischen MCI-Patienten mit versus ohne depressiver Symptomatik (AUC = .634, p
ADHD (attention-deficit hyperactivity disorder) and academic difficulties are frequently associat... more ADHD (attention-deficit hyperactivity disorder) and academic difficulties are frequently associated, but to date this link is poorly understood. In order to explore which components of number processing and calculation skills may be disturbed in children with ADHD we presented a series of respective tasks to 9-to 12-year-old children with ADHD-combined type and matched children without ADHD (of any type) without concomitant dyscalculia and/or dyslexia. Overall, group differences were not significant regarding overlearned and explicitly trained simple and complex calculation skills. More basic number processing skills are-for instance-the ability to compare one-digit numbers according to their magnitude (so-called magnitude comparison), to count or to transcode numbers, i.e. to write down an Arabic number '21' in verbal dictation. Significant differences favouring control children in basic number processing skills were obtained in a number comparison task and in a dot enumeration task. Importantly, our results cannot be explained by group differences regarding specific working memory and executive function components. Thus, number processing skills and in particular the processing of numerical magnitude should be investigated in children diagnosed with ADHD even when no comorbid learning disabilities are reported.
The mental number line of children is usually assumed to be language-independent; however, this i... more The mental number line of children is usually assumed to be language-independent; however, this independency has not yet been studied. In this cross-cultural study, we examined the influence of language properties on a nonverbal version of the number line task in Italian- and German-speaking first graders. The essential difference between the two languages concerns the inversion property of most German multi-digit numbers (e.g., 48 → “eight-and-forty”), whereas in Italian number-words no inversion is found. The analyses revealed two language-specific differences in the number line task: (a) Generally, the estimates of Italian children were more accurate than those of Austrian children, even when controlling for general cognitive abilities. (b) Italian children performed particularly better when inversion errors led to large estimation errors. In conclusion, these findings indicate that the organization of children’s mental number line is indeed influenced by language properties even in nonverbal settings.
Low numeracy skills have a negative impact on the employment prospects and mental and physical he... more Low numeracy skills have a negative impact on the employment prospects and mental and physical health of individuals, and on the economic status of countries. Clearly, this is a high priority area where efficient strategies for intervention can lead to a better outcome, especially when implemented at an early age. We discuss here present and future directions for intervention. The development of such interventions has been based on the study of numerical difficulties through methods ranging from standardized tests to behavioral measures to neuroimaging. The intervention techniques range from group-based interventions targeted at strengths and weaknesses in specific components of arithmetic, to educational computergames, to non-invasive brain-stimulation. We discuss the principles behind each method, the current evidence, and future directions.
Severe congenital heart disease (CHD) occurs in six out of thousand live born children (Hoffman &... more Severe congenital heart disease (CHD) occurs in six out of thousand live born children (Hoffman & Kaplan, 2002). Thereof, about 50% require cardio-pulmonary bypass surgery. Major improvements in surgical procedures and techniques have led to a significant decrease in mortality and improved cardiac outcome (Nieminen, Jokinen, & Sairanen, 2007). Nonetheless,
Background/aims Being born small-for-gestational-age (SGA), a proxy for fetal growth restriction ... more Background/aims Being born small-for-gestational-age (SGA), a proxy for fetal growth restriction (FGR) has been related to poor school performance, lower academic achievement and cognitive problems. The aim of this study was to investigate whether young adults born SGA at term had reduced brain volumes, cortical surface area and/or cortical thickness, and whether brain morphometry measures were related to cognitive functioning. Methods In this population-based follow-up study at age 20, 58 term-born SGA (birthweight < 10 th centile, mean: 2915 g) and 81 non-SGA controls (birthweight >10 th centile, mean: 3707 g) were included. MRI-examinations at 1.5 T were obtained in 47 SGA and 61 control subjects. Image analysis was performed by the FreeSurfer, version 5.1. IQ was assessed by Wechsler Adult Intelligence Scale 3rd edition (WAIS-III). Results Total brain volume was smaller in the SGA than in the control group (-5.6%; p < 0.001). This reduction included most structures, but relative volumes were the same. Cortical surface area was significantly reduced in the SGA group compared with controls in multiple regions across the cerebral cortex, especially in the frontal, parietal and temporal lobes compared with controls (Figure). The reduction in surface area in the SGA group was most pronounced in the anterior cingulate gyri bilaterally. No associations were found between brain measures and IQ measures in either group. Conclusions Young adults born SGA at term have a global reduction in brain volume and regional reductions in cortical surface area. This may have long term consequences for cognitive functioning.
This article focuses on typical trajectories of numerical cognition from infancy all the way thro... more This article focuses on typical trajectories of numerical cognition from infancy all the way through to adulthood (please note that atypical pathways of numerical cognition will be dealt in‘Brain Correlates of Numerical Disabilities’). Despite the fact that developmental imaging studies are still scarce to date there is converging evidence that (1) neural signatures of non-verbal number processing may be observed already in infants; and (2) developmental changes in neural responsivity are characterized by increasing functional specialization of number-relevant frontoparietal brain regions. It has been suggested that age and competence-related modulations of brain activity manifest as an anterior-posterior shift. On the one hand, the recruitment of supporting frontal brain regions decreases, while on the other hand, reliance on number-relevant (fronto-)parietal neural networks increases. Overall, our understanding of the neurocognitive underpinnings of numerical development grew considerably during the last decade. Future research is expected to benefit substantially from the fast technological advances enabling researchers to gain more fine-grained insights into the spatial and temporal dynamics of the neural signatures underlying numerical development.
What are the brain correlates of numerical disabilities? To date only few studies have examined t... more What are the brain correlates of numerical disabilities? To date only few studies have examined the neuronal underpinnings of specific numerical learning disabilities like developmental dyscalculia (DD). However, first results provide important insights if and where brains of children diagnosed with DD differ from those of typically achieving peers. Main deficits are apparent in core regions for number processing, which mainly comprise gray, as well as white matter in parietal lobes. Moreover, it already can be demonstrated that brain activation in DD is changing according to learning and intervention. The present chapter will bring together existing puzzle pieces of brain imaging findings in DD, as well as highlight some critical issues that have to be considered when comparing studies including children with DD.
Dieses Kapitel umfasst die umschriebenen Entwicklungsstorungen schulischer Fertigkeiten, von Lese... more Dieses Kapitel umfasst die umschriebenen Entwicklungsstorungen schulischer Fertigkeiten, von Lese-Rechtschreib-Storungen, Rechenstorungen bis zu kombinierten Storungen. Neben Informationen zu Klassifikation, Epidemiologie, Atiologie, Symptomatik, Diagnostik und Therapieverfahren finden sich auch zahlreiche praktische Tipps und Hilfestellungen fur den Alltag in Praxis und Klinik wieder.
Attention deficit hyperactivity disorder (ADHD) is characterized by deficient self-regulation, po... more Attention deficit hyperactivity disorder (ADHD) is characterized by deficient self-regulation, poor attentional control, and poor response inhibition. To date, however, the extent to which these deficits affect basic interference control remains a matter of controversy. Secondly, ADHD has been reported to be associated with arithmetic deficits. It remains unclear whether such deficits are a secondary consequence of the above-mentioned characteristics of ADHD or whether basic numerical magnitude representations are also affected. In the present study we attempted to investigate these issues using a basic numerical interference paradigm. Nine- to twelve-year-old children with ADHD-C (attention-deficit hyperactivity-disorder combined type) and control children without ADHD (each n = 16) were presented with two digits of possibly different physical sizes (e.g., 3 7). This numerical Stroop task requires subjects to make a magnitude classification concerning either the physical or the numerical stimulus dimension. The irrelevant dimension can be congruent (same response), incongruent (different response), or neutral (no response association). Children with ADHD-C performed worse than control children in most analyses. The most important finding was a significant interaction of congruity effects with group in the numerical comparison task. Children with ADHD-C tended to show larger congruity and interference effects than controls, and these were not attributable to a speed-accuracy trade-off. The results might reflect differential processing speeds, or a different degree of automatic activation of physical and numerical magnitudes in children with and without ADHD-C. Alternative explanations, such as insufficient inhibition of selective (domain-specific) attention are also discussed.
Dyskalkulie (umschriebene Rechenstörung) wurde bis vor wenigen Jahren noch kaum als Teilleistungs... more Dyskalkulie (umschriebene Rechenstörung) wurde bis vor wenigen Jahren noch kaum als Teilleistungsstörung beschrieben. In den letzten 5 Jahren scheint Dyskalkulie als Störung in Mode zu kommen und Dyskalkulie-Therapie wird verstärkt nachgefragt und angeboten. Im Gegensatz zur Legasthenie ist die Forschung zur Dyskalkulie aber noch sehr jung und der Stand des Wissens verändert sich rasant. In diesem Artikel wird zunächst beschrieben, was wir 2006 über das Syndrom und seine neurokognitiven Grundlagen wissen, wie wir es modelltheoretisch beschreiben können, wie man es diagnostizieren kann und worauf man bei Interventionen achten muss.
Das Hauptziel dieser retrospektiven Studie war die Untersuchung des differentialdiagnostischen Nu... more Das Hauptziel dieser retrospektiven Studie war die Untersuchung des differentialdiagnostischen Nutzens der CERAD neuropsychologischen Testbatterie zur Unterscheidung geriatrischer Patienten mit leichter kognitiver Störung/MCI (n = 345) mit versus ohne depressiver Symptomatik. Alle Analysen wurden doppelt gerechnet (ICD-10-konforme MCI-Definition und amnestische MCI/a-MCI). Die optimalen empirischen Cutoff-Werte und die diagnostische Genauigkeit wurden mittels Receiver Operating Characteristic/ROC-Analysen berechnet. Die Ergebnisse sind abhängig vom verwendeten MCI-Definitionskriterium und bestätigen die differentialdiagnostische Nützlichkeit der CERAD, allerdings ausschließlich bei Verwendung ICD-10-konformer Definitionskriterien (nicht bei a-MCI). Der CERAD-Summenwert differenziert signifikant zwischen MCI-Patienten mit versus ohne depressiver Symptomatik (AUC = .634, p
ADHD (attention-deficit hyperactivity disorder) and academic difficulties are frequently associat... more ADHD (attention-deficit hyperactivity disorder) and academic difficulties are frequently associated, but to date this link is poorly understood. In order to explore which components of number processing and calculation skills may be disturbed in children with ADHD we presented a series of respective tasks to 9-to 12-year-old children with ADHD-combined type and matched children without ADHD (of any type) without concomitant dyscalculia and/or dyslexia. Overall, group differences were not significant regarding overlearned and explicitly trained simple and complex calculation skills. More basic number processing skills are-for instance-the ability to compare one-digit numbers according to their magnitude (so-called magnitude comparison), to count or to transcode numbers, i.e. to write down an Arabic number '21' in verbal dictation. Significant differences favouring control children in basic number processing skills were obtained in a number comparison task and in a dot enumeration task. Importantly, our results cannot be explained by group differences regarding specific working memory and executive function components. Thus, number processing skills and in particular the processing of numerical magnitude should be investigated in children diagnosed with ADHD even when no comorbid learning disabilities are reported.
The mental number line of children is usually assumed to be language-independent; however, this i... more The mental number line of children is usually assumed to be language-independent; however, this independency has not yet been studied. In this cross-cultural study, we examined the influence of language properties on a nonverbal version of the number line task in Italian- and German-speaking first graders. The essential difference between the two languages concerns the inversion property of most German multi-digit numbers (e.g., 48 → “eight-and-forty”), whereas in Italian number-words no inversion is found. The analyses revealed two language-specific differences in the number line task: (a) Generally, the estimates of Italian children were more accurate than those of Austrian children, even when controlling for general cognitive abilities. (b) Italian children performed particularly better when inversion errors led to large estimation errors. In conclusion, these findings indicate that the organization of children’s mental number line is indeed influenced by language properties even in nonverbal settings.
Low numeracy skills have a negative impact on the employment prospects and mental and physical he... more Low numeracy skills have a negative impact on the employment prospects and mental and physical health of individuals, and on the economic status of countries. Clearly, this is a high priority area where efficient strategies for intervention can lead to a better outcome, especially when implemented at an early age. We discuss here present and future directions for intervention. The development of such interventions has been based on the study of numerical difficulties through methods ranging from standardized tests to behavioral measures to neuroimaging. The intervention techniques range from group-based interventions targeted at strengths and weaknesses in specific components of arithmetic, to educational computergames, to non-invasive brain-stimulation. We discuss the principles behind each method, the current evidence, and future directions.
Severe congenital heart disease (CHD) occurs in six out of thousand live born children (Hoffman &... more Severe congenital heart disease (CHD) occurs in six out of thousand live born children (Hoffman & Kaplan, 2002). Thereof, about 50% require cardio-pulmonary bypass surgery. Major improvements in surgical procedures and techniques have led to a significant decrease in mortality and improved cardiac outcome (Nieminen, Jokinen, & Sairanen, 2007). Nonetheless,
Background/aims Being born small-for-gestational-age (SGA), a proxy for fetal growth restriction ... more Background/aims Being born small-for-gestational-age (SGA), a proxy for fetal growth restriction (FGR) has been related to poor school performance, lower academic achievement and cognitive problems. The aim of this study was to investigate whether young adults born SGA at term had reduced brain volumes, cortical surface area and/or cortical thickness, and whether brain morphometry measures were related to cognitive functioning. Methods In this population-based follow-up study at age 20, 58 term-born SGA (birthweight < 10 th centile, mean: 2915 g) and 81 non-SGA controls (birthweight >10 th centile, mean: 3707 g) were included. MRI-examinations at 1.5 T were obtained in 47 SGA and 61 control subjects. Image analysis was performed by the FreeSurfer, version 5.1. IQ was assessed by Wechsler Adult Intelligence Scale 3rd edition (WAIS-III). Results Total brain volume was smaller in the SGA than in the control group (-5.6%; p < 0.001). This reduction included most structures, but relative volumes were the same. Cortical surface area was significantly reduced in the SGA group compared with controls in multiple regions across the cerebral cortex, especially in the frontal, parietal and temporal lobes compared with controls (Figure). The reduction in surface area in the SGA group was most pronounced in the anterior cingulate gyri bilaterally. No associations were found between brain measures and IQ measures in either group. Conclusions Young adults born SGA at term have a global reduction in brain volume and regional reductions in cortical surface area. This may have long term consequences for cognitive functioning.
This article focuses on typical trajectories of numerical cognition from infancy all the way thro... more This article focuses on typical trajectories of numerical cognition from infancy all the way through to adulthood (please note that atypical pathways of numerical cognition will be dealt in‘Brain Correlates of Numerical Disabilities’). Despite the fact that developmental imaging studies are still scarce to date there is converging evidence that (1) neural signatures of non-verbal number processing may be observed already in infants; and (2) developmental changes in neural responsivity are characterized by increasing functional specialization of number-relevant frontoparietal brain regions. It has been suggested that age and competence-related modulations of brain activity manifest as an anterior-posterior shift. On the one hand, the recruitment of supporting frontal brain regions decreases, while on the other hand, reliance on number-relevant (fronto-)parietal neural networks increases. Overall, our understanding of the neurocognitive underpinnings of numerical development grew considerably during the last decade. Future research is expected to benefit substantially from the fast technological advances enabling researchers to gain more fine-grained insights into the spatial and temporal dynamics of the neural signatures underlying numerical development.
What are the brain correlates of numerical disabilities? To date only few studies have examined t... more What are the brain correlates of numerical disabilities? To date only few studies have examined the neuronal underpinnings of specific numerical learning disabilities like developmental dyscalculia (DD). However, first results provide important insights if and where brains of children diagnosed with DD differ from those of typically achieving peers. Main deficits are apparent in core regions for number processing, which mainly comprise gray, as well as white matter in parietal lobes. Moreover, it already can be demonstrated that brain activation in DD is changing according to learning and intervention. The present chapter will bring together existing puzzle pieces of brain imaging findings in DD, as well as highlight some critical issues that have to be considered when comparing studies including children with DD.
Dieses Kapitel umfasst die umschriebenen Entwicklungsstorungen schulischer Fertigkeiten, von Lese... more Dieses Kapitel umfasst die umschriebenen Entwicklungsstorungen schulischer Fertigkeiten, von Lese-Rechtschreib-Storungen, Rechenstorungen bis zu kombinierten Storungen. Neben Informationen zu Klassifikation, Epidemiologie, Atiologie, Symptomatik, Diagnostik und Therapieverfahren finden sich auch zahlreiche praktische Tipps und Hilfestellungen fur den Alltag in Praxis und Klinik wieder.
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