Michael von Aster

Impaired neural networks for approximate calculation in dyscalculic children: a functional MRI study

BackgroundDevelopmental dyscalculia (DD) is a specific learning disability affecting the acquisition of mathematical skills in children with otherwise normal general intelligence. The goal of the present study was to examine cerebral mechanisms underlying DD.MethodsEighteen children with DD aged 11.2 ± 1.3 years and twenty age-matched typically achieving schoolchildren were investigated using functional magnetic resonance imaging (fMRI) during trials testing approximate and exact mathematical calculation, as well as magnitude comparison.ResultsChildren with DD showed greater inter-individual variability and had weaker activation in almost the entire neuronal network for approximate calculation including the intraparietal sulcus, and the middle and inferior frontal gyrus of both hemispheres. In particular, the left intraparietal sulcus, the left inferior frontal gyrus and the right middle frontal gyrus seem to play crucial roles in correct approximate calculation, since brain activation correlated with accuracy rate in these regions. In contrast, no differences between groups could be found for exact calculation and magnitude comparison. In general, fMRI revealed similar parietal and prefrontal activation patterns in DD children compared to controls for all conditions.ConclusionIn conclusion, there is evidence for a deficient recruitment of neural resources in children with DD when processing analog magnitudes of numbers.

Development of neural networks for exact and approximate calculation: a FMRI study.

Neuroimaging findings in adults suggest exact and approximate number processing relying on distinct neural circuits. In the present study we are investigating whether this cortical specialization is already established in 9- and 12-year-old children. Using fMRI, brain activation was measured in 10 third- and 10 sixth-grade school children and 20 adults during trials of symbolic approximate (AP) and exact (EX) calculation, as well as non-symbolic magnitude comparison (MC) of objects. Children activated similar networks like adults, denoting an availability and a similar spatial extent of specified networks as early as third grade. However, brain areas related to number processing become further specialized with schooling. Children showed weaker activation in the intraparietal sulcus during all three tasks, in the left inferior frontal gyrus during EX and in occipital areas during MC. In contrast, activation in the anterior cingulate gyrus, a region associated with attentional effort and working memory load, was enhanced in children. Moreover, children revealed reduced or absent deactivation of regions involved in the so-called default network during symbolic calculation, suggesting a rather general developmental effect. No difference in brain activation patterns between AP and EX was found. Behavioral results indicated major differences between children and adults in AP and EX, but not in MC. Reaction time and accuracy rate were not correlated to brain activation in regions showing developmental changes suggesting rather effects of development than performance differences between children and adults. In conclusion, increasing expertise with age may lead to more automated processing of mental arithmetic, which is reflected by improved performance and by increased brain activation in regions related to number processing and decreased activation in supporting areas.

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.

Dyscalculia from a developmental and differential perspective.

Developmental dyscalculia (DD) and its treatment are receiving increasing research attention. A PsychInfo search for peer-reviewed articles with dyscalculia as a title word reveals 31 papers published from 1991–2001, versus 74 papers published from 2002–2012. Still, these small counts reflect the paucity of research on DD compared to dyslexia, despite the prevalence of mathematical difficulties. In the UK, 22% of adults have mathematical difficulties sufficient to impose severe practical and occupational restrictions (Bynner and Parsons, 1997; National Center for Education Statistics, 2011). It is unlikely that all of these individuals with mathematical difficulties have DD, but criteria for defining and diagnosing dyscalculia remain ambiguous (Mazzocco and Myers, 2003). What is treated as DD in one study may be conceptualized as another form of mathematical impairment in another study. Furthermore, DD is frequently—but, we believe, mistakenly- considered a largely homogeneous disorder. Here we advocate a differential and developmental perspective on DD focused on identifying behavioral, cognitive, and neural sources of individual differences that contribute to our understanding of what DD is and what it is not.

Die Entwicklung räumlicher Zahlenrepräsentationen und Rechenfertigkeiten bei Kindern

Zusammenfassung: Hintergrund: Die Reprasentation der Grose von Zahlen in einem von links nach rechts orientierten mentalen Zahlenstrahl wurde bei Erwachsenen mit dem SNARC-Effektes dargestellt (Spatial Numerical Association of Response Codes: schnellere Reaktion linke Hand bei kleinen Zahlen und rechte Hand bei grosen Zahlen; Dehaene, Bossini & Giraux; 1993). Fragestellung: Die Studie untersucht die Frage, ob SNARC-Effekte (SE) schon bei Kindern der 2. Klasse nachweisbar sind und welche Zusammenhange zu Rechenleistungen bestehen. Methode: Untersucht wurden N = 113 Kinder aus einer reprasentativen Stichprobe aus dem Kanton Zurich. Die Uberprufung von Fertigkeiten der Zahlenverarbeitung erfolgte longitudinal im Kindergarten und in der 2. Klasse. Ebenfalls zum zweiten Testzeitpunkt erfolgte die Durchfuhrung des computergestutzten SNARC-Paradigmas. Ergebnisse/Diskussion: Etwa ein Drittel der Kinder zeigten einen SE. Uber die gesamte Stichprobe lies sich kein signifikanter Einfluss des SE auf die Testleistung ...

Mathematics Education and Neuroscience

The interdisciplinary research field of educational neuroscience – linking neuroscience, psychology, and education – has witnessed a tremendous growth in the past five to ten years. By combining behavioral and neuroscientific methods, its general aim is to achieve a broader understanding of the neurocognitive mechanisms underlying learning and to support the development of effective instruction. A considerable impetus for the growth of educational neuroscience came from research on mathematics learning. Some of these findings have been presented in special issues in the journal ZDM Mathematics Education, in 2010 and 2016. Despite the field’s success, it has been repeatedly questioned whether the obtained neuroscientific evidence has implications for education (including research and practice) or whether the connection between neuroscience and education is a bridge too far (e.g., Ansari & Lyons, 2016; Bowers, 2016). Has the inclusion of the neuroscientific level of analysis furthered our understanding of successful mathematics learning and how to support it? These questions can only be answered from an interdisciplinary perspective. The aim of this discussion group is to bring together neuroscientists, psychologists, and math educators, and to discuss the chances and limitations of educational neuroscience research on selected topics of mathematics education.

Endlich Realität: Wissenschaft und Anwendung im Dialog

im dritten Jahr des Bestehens unserer Zeitschrift Lernen und Lernstorungen freuen wir uns sehr, Ihnen die Zeitschrift in einer neuen Gestalt prasentieren zu konnen. Die Zeitschrift wird ab Januar 2014 – also beginnend mit dieser Ausgabe – um einen anwendungsorientierten Teil erweitert, der sich durch einen hohen Praxisbezug auszeichnen soll und speziell auf die Zielgruppe der Anwender zugeschnitten ist. Zu diesem Zweck wird die Zeitschrift zunachst in einem Probejahrgang unter Beteiligung des Fachverbandes fur integrative Lerntherapie e. V. (FiL) herausgegeben und das Herausgebergremium um Frau Prof. Dr. Cordula Loffl er, Fachdidaktik Deutsch, und Frau Prof. Dr. Marianne Nolte, Fachdidaktik Mathematik, erweitert. Einzelne Inhalte der Zeitschrift SPRACHROHR des FiL werden in diesen neuen Teil unserer Zeitschrift einfl iesen. Lernen und Lernstorungen wird damit auch als Mitgliederzeitschrift des FiL fungieren. Wir begrusen die neue Leserschaft herzlich und freuen uns auf Ruckmeldungen und den gemeinsamen Dialog.