Core deficit and individual manifestations of developmental dyscalculia (DD): The role of comorbidity

2013 ◽  
Vol 2 (2) ◽  
pp. 38-42 ◽  
Author(s):  
Karin Landerl ◽  
Silke M. Göbel ◽  
Kristina Moll
Keyword(s):  
Developmental Dyscalculia ◽  
Core Deficit

Nonsymbolic-Magnitude Deficit in Adults With Developmental Dyscalculia: Evidence of Impaired Size Discrimination but Intact Size Constancy

2021 ◽  
pp. 095679762199520
Author(s):  
Nirit Fooks ◽  
Bat-Sheva Hadad ◽  
Orly Rubinsten
Keyword(s):  
Size Constancy ◽  
Size Discrimination ◽  
Depth Cues ◽  
Developmental Dyscalculia ◽  
Core Deficit ◽  
Depth Ordering

Although researchers have debated whether a core deficit of nonsymbolic representation of magnitude underlies developmental dyscalculia (DD), research has mostly focused on numerosity processing. We probed the possibility of a general magnitude deficit in individuals with DD and asked whether sensitivity to size varied in contexts of depth ordering and size constancy. We measured full psychometric functions in size-discrimination tasks in 12 participants with DD and 13 control participants. Results showed that although people with DD exhibited veridical perceived magnitude, their sensitivity to size was clearly impaired. In contrast, when objects were embedded in depth cues allowing size-constancy computations, participants with DD demonstrated typical sensitivity to size. These results demonstrate a deficit in the perceptual resolutions of magnitude in DD. At the same time, the finding of an intact size constancy suggests that when magnitude perception is facilitated by implicit mandatory computations of size constancy, this deficit is no longer evident.

Developmental Dyscalculia in Adults: Beyond Numerical Magnitude Impairment

2017 ◽  
Vol 51 (6) ◽  
pp. 600-611 ◽  
Author(s):  
Alice De Visscher ◽  
Marie-Pascale Noël ◽  
Mauro Pesenti ◽  
Valérie Dormal
Keyword(s):  
Mental Representation ◽  
Healthy Adults ◽  
Numerical Magnitude ◽  
Developmental Dyscalculia ◽  
Common System ◽  
The Core ◽  
Magnitude Processing ◽  
Core Deficit ◽  
Face Categorization ◽  
Numerical Magnitudes

Numerous studies have tried to identify the core deficit of developmental dyscalculia (DD), mainly by assessing a possible deficit of the mental representation of numerical magnitude. Research in healthy adults has shown that numerosity, duration, and space share a partly common system of magnitude processing and representation. However, in DD, numerosity processing has until now received much more attention than the processing of other non-numerical magnitudes. To assess whether or not the processing of non-numerical magnitudes is impaired in DD, the performance of 15 adults with DD and 15 control participants was compared in four categorization tasks using numerosities, lengths, durations, and faces (as non-magnitude-based control stimuli). Results showed that adults with DD were impaired in processing numerosity and duration, while their performance in length and face categorization did not differ from controls’ performance. Our findings support the idea of a nonsymbolic magnitude deficit in DD, affecting numerosity and duration processing but not length processing.

Developmental Dyscalculia

2015 ◽  
Vol 223 (2) ◽  
pp. 69-82 ◽  
Author(s):  
Jörg-Tobias Kuhn
Keyword(s):  
Number Processing ◽  
Cognitive Resources ◽  
Cognitive Profiles ◽  
Developmental Dyscalculia ◽  
Hyperactivity Disorder ◽  
Magnitude Processing ◽  
Specific Learning Disorder ◽  
Behavioral Evidence ◽  
Fact Retrieval

Developmental dyscalculia (DD) is a specific learning disorder that affects the acquisition of arithmetic skills and number processing in children. A high comorbidity between DD and other neurodevelopmental disorders (e.g., dyslexia, attention-deficit/hyperactivity disorder [ADHD]) as well as substantial heterogeneity in cognitive profiles have been reported. Current studies indicate that DD is persistent, has a genetic component, and is related to functional and structural alterations of brain areas involved in magnitude representation. Recent neuronal and behavioral evidence is presented, showing that DD entails (a) impairments in two preverbal core systems of number, an approximate system for estimating larger magnitudes and an exact system for representing small magnitudes, (b) deficits in symbolic number processing, (c) aberrant and nonadaptive neuronal activation in basic magnitude processing and calculation, (d) dysfunctional arithmetic fact retrieval and persistent use of counting strategies in calculation, and (e) deficits in visuospatial working memory and the central executive. Finally, open research questions, including the role of domain-general cognitive resources in DD, causes and developmental consequences of comorbidity, as well as design and evaluation of interventions for DD, are briefly discussed.

Refining the Phonological Core Deficit Model

1998 ◽  
Vol 3 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Keith E. Stanovich
Keyword(s):  
Reading Disability ◽  
Recent Work ◽  
Deficit Model ◽  
Core Deficit

Despite some disagreements among the respective authors, the previous two articles contain many thoughtful recommendations about how to conceptualise reading disability. My reactions will be organised around two issues: the role of intelligence in understanding reading disability and the implications that recent work on subtypes has for the phonological core deficit model.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

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