Two Dyscalculia Subtypes With Similar, Low Comorbidity Profiles: A Mixture Model Analysis

Several studies have aimed to identify subtypes of dyscalculia. In many of these studies, either pre-defined groups (e.g., children with reading and mathematical difficulties vs. children with isolated mathematical difficulties) were analyzed regarding their cognitive profiles (top-down approach), or clusters of children with dyscalculia (CwD) were identified based on a narrow range of cognitive and mathematical skills (data-driven or bottom-up approach). However, it has remained difficult to establish robust subtypes of dyscalculia across studies. Against this background, we conducted a mixture model analysis in order to explore and identify subtypes of dyscalculia based on a broad range of variables (intelligence, reading fluency, working memory, attention, and various mathematical skills). The total sample comprised 174 elementary school CwD (IQ > 70; mathematical abilities: percentile rank <10), which consisted of two subsamples. The first subsample was based on a diagnostic test focusing on calculation (HRT 1–4; n = 71; 46 girls, 25 boys; age: M = 9.28 years, SD = 0.94) whereas the second subsample was based on a diagnostic test with a strong focus on basic numerical capacities (ZAREKI-R; n = 103; 78 girls, 25 boys; age: M = 8.94 years, SD = 1.05). Results provided convincing evidence for the existence of two subtypes in CwD: A slightly impaired subtype and a strongly impaired subtype. Subtypes differed most strongly regarding mathematical abilities, but the analyses suggest that differences in attention could also be a key factor. Therefore, comorbid attention difficulties seem to be a relevant factor that needs to be considered when establishing subtypes. Substantial intelligence differences between dyscalculia subtypes could not be found. Differences in working memory and reading fluency were negligible. Overall, the results seemed to be robust regardless of the diagnostic test used for assessing dyscalculia. When planning interventions for CwD, the existence of a subtype with substantial attention problems should be kept in mind

‘Forget me (not)?’ – Remembering Forget-Items Versus Un-Cued Items in Directed Forgetting

Zwissler B, Schindler S, Fischer H, Plewnia C, Kißler J. ‘Forget me (not)?’ – Remembering Forget-Items Versus Un-Cued Items in Directed Forgetting. Frontiers in Psychology. 2015;6: 1741.Humans need to be able to selectively control their memories. This capability is often investigated in directed forgetting (DF) paradigms. In item-method DF, individual items are presented and each is followed by either a forget- or remember-instruction. On a surprise test of all items, memory is then worse for to-be-forgotten items (TBF) compared to to-be-remembered items (TBR). This is thought to result mainly from selective rehearsal of TBR, although inhibitory mechanisms also appear to be recruited by this paradigm. Here, we investigate whether the mnemonic consequences of a forget instruction differ from the ones of incidental encoding, where items are presented without a specific memory instruction. Four experiments were conducted where un-cued items (UI) were interspersed and recognition performance was compared between TBR, TBF, and UI stimuli. Accuracy was encouraged via a performance-dependent monetary bonus. Experiments varied the number of items and their presentation speed and used either letter-cues or symbolic cues. Across all experiments, including perceptually fully counterbalanced variants, memory accuracy for TBF was reduced compared to TBR, but better than for UI. Moreover, participants made consistently fewer false alarms and used a very conservative response criterion when responding to TBF stimuli. Thus, the F-cue results in active processing and reduces false alarm rate, but this does not impair recognition memory beyond an un-cued baseline condition, where only incidental encoding occurs. Theoretical implications of these findings are discussed

Shaping Memory Accuracy by Left Prefrontal Transcranial Direct Current Stimulation

Zwissler B, Sperber C, Aigeldinger S, Schindler S, Kißler J, Plewnia C. Shaping Memory Accuracy by Left Prefrontal Transcranial Direct Current Stimulation. Journal of Neuroscience. 2014;34(11):4022-4026.Human memory is dynamic and flexible but is also susceptible to distortions arising from adaptive as well as pathological processes. Both accurate and false memory formation require executive control that is critically mediated by the left prefrontal cortex (PFC). Transcranial direct current stimulation (tDCS) enables noninvasive modulation of cortical activity and associated behavior. The present study reports that tDCS applied to the left dorsolateral PFC (dlPFC) shaped accuracy of episodic memory via polaritiy-specific modulation of false recognition. When applied during encoding of pictures, anodal tDCS increased whereas cathodal stimulation reduced the number of false alarms to lure pictures in subsequent recognition memory testing. These data suggest that the enhancement of excitability in the dlPFC by anodal tDCS can be associated with blurred detail memory. In contrast, activity-reducing cathodal tDCS apparently acted as a noise filter inhibiting the development of imprecise memory traces and reducing the false memory rate. Consistently, the largest effect was found in the most active condition (i.e., for stimuli cued to be remembered). This first evidence for a polarity-specific, activity-dependent effect of tDCS on false memory opens new vistas for the understanding and potential treatment of disturbed memory control

Appbasierte Förderansätze für Kinder mit Lernstörungen

Hintergrund: Einstellungen zu digitalen Fördermaßnahmen wurden bislang hauptsächlich aus der Sicht von Lehrkräften untersucht, obwohl das Lernen mit digitalen Hilfsmitteln im häuslichen Umfeld an Bedeutung gewinnt. Deshalb wird der Frage nachgegangen, wie Angehörige/Eltern von Kindern mit Lernstörungen (= KmL: Rechenstörung, Lesestörung bzw. kombinierte Lernstörung) die Förderung mit Trainings-Apps via Tablet in der häuslichen Umgebung erleben und was für sie in diesem Kontext wichtig ist. Methoden: Mithilfe leitfadengestützter Expert_inneninterviews wurden 21 Angehörige von KmL und zwei Projektbegleiterinnen, die im regelmäßigen Austausch mit den Angehörigen standen, interviewt; zusätzlich wurden mit einem schriftlichen Fragebogen qualitative Datensätze zum Lernerleben mit den Apps sowie zur allgemeinen Wahrnehmung der Apps aus der Perspektive von 1) KmL (n = 83), welche die Trainings-App genutzt haben, und 2) weiteren Angehörigen (n = 81) erhoben. Ergebnis: Durch qualitative Analysen wurden Gelingensbedingungen (z.B. das Engagement der Angehörigen), aber auch Herausforderungen für die Verwendung von Trainings-Apps (z.B. technische Schwierigkeiten, Missverständnisse, Qualität der Stimmausgabe, als unpassend empfundener Schwierigkeitsgrad) herausgearbeitet. Diskussion: Aktuell wird das Training wahlweise als zu schwer, zu leicht oder zu ausufernd wahrgenommen. Um hier eine individuelle Passung zu erreichen, ist weitere Forschung sowie Entwicklung notwendig.Background: While learning with digital tools gains increasing importance, attitudes towards digital intervention tools have so far mainly been investigated from the perspective of teachers. Therefore, the question is investigated how relatives/parents of children with specific educational learning disorders (= CwLD: dyscalculia, reading disorder or combined learning disorder) experience the support with training apps via tablet in their home environment and what is important for them in this context. Methods: Using guideline-based expert interviews, 21 relatives of CwLD and two female employees, who worked as technical support and were in regular contact with the relatives, were interviewed; in addition, a questionnaire was used to collect qualitative data sets on the learning experience with the apps and on the general perceptions of the apps from the perspective of 1) the CwLD (n = 83) who used the training app and 2) other relatives (n = 81). Results: With qualitative analyses conditions for success (e.g., engagement of relatives) but also limitations to the use of training apps (e.g., technical difficulties, misunderstandings, voice output, perceived inappropriateness of training difficulty) were identified. Discussion: Currently, training is perceived as either too difficult, too easy, or too extensive. To achieve an individual fit, further research and development is necessary

Ein simulierter Datensatz zur Erprobung und Veranschaulichung quantitativer Methoden der Datenanalyse

Dieser Datensatz wurde von Christian Kißler mit R simuliert. Die Daten in diesem Datensatz stellen keine tatsächlich erhobenen Daten dar, sondern wurden generiert, um mit ihnen statistische Prinzipien verdeutlichen zu können. Der Datensatz ist daher insbesondere für Lehrzwecke geeignet. Der Datensatz darf frei verwendet sowie bearbeitet und verbreitet werden, insofern der Autor nach den Gepflogenheiten zur Angabe wissenschaftlicher Quellen korrekt angegeben wird. Empfehlung zur Quellenangabe: "Kißler, Christian (2023). Ein simulierter Datensatz zur Erprobung und Veranschaulichung quantitativer Methoden der Datenanalyse. Eldorado." Dieser Datensatz gehört zu dem Buch: „Eine praktische Einführung in die Statistik mit R und RStudio – Ein Lehrskript für Studierende der Rehabilitationspädagogik, Rehabilitationswissenschaften sowie (Sonder-)Pädagogik“ von Christian Kißler, Florian Krieger und Jörg-Tobias Kuhn

R-Skript zum Lehrwerk "Eine praktische Einführung in die Statistik mit R und RStudio" von Christian Kißler, Florian Krieger und Jörg-Tobias Kuhn

Dies ist das ergänzende R-Skript zum Manuskript/ Buch mit dem Titel: "Eine praktische Einführung in die Statistik mit R und RStudio - Ein Lehrskript für Studierende der Rehabilitationspädagogik, Rehabilitationswissenschaften sowie (Sonder-)Pädagogik" von Christian Kißler, Florian Krieger und Jörg-Tobias Kuhn