Issue 23: Developmental Dyscalculia: A Research Overview | Dr Anneke Schreuder

Developmental dyscalculia is a specific learning disability that primarily affects an individual's ability to understand and manipulate numbers. This disorder typically manifests in early elementary years, often presenting as difficulty with basic arithmetic, and may later extend to challenges with abstract mathematical concepts. Despite gaining increased attention in recent years, developmental dyscalculia lags behind dyslexia in terms of awareness, research funding, and treatment development.

Historical Context

The recognition of dyscalculia as a distinct learning disability has evolved over the past century. In 1919, Swedish neurologist Dr. Salomon Henschen observed that individuals with otherwise normal mental abilities could experience significant difficulties with numbers. Dr. Josef Gerstmann's work in 1940 identified a syndrome characterized by difficulties in writing (dysgraphia), arithmetic (later termed dyscalculia), finger agnosia (not knowing which finger is touched when not visible), and left-right coordination. Dr. Ladislav Kosc, in the 1950s, first described developmental dyscalculia as a disorder affecting math-related brain functions, potentially hereditary or congenital in nature.

Development of Number Sense

Research has shown that numerical awareness begins in infancy, with babies demonstrating the ability to distinguish small quantities. As children develop, they progress through several key stages. As toddlers, they realize that if you put three blocks in a row or scattered, there are still three blocks, and also that their colors or shapes don't matter, but when you add one or take away one, the number does change; this is called quantity conservation. They start reciting number words out of order or sometimes string them together into one long word before they connect each counting word with an item by moving it or pointing at it. They have developed what they call one-to-one correspondence. During Pre-K, they begin counting on their fingers, and they realize that the number of objects in a group is the last word you hear when you have finished counting. We call this cardinality. They enjoy demonstrating their newly learned skill of counting the pips on dice and dominoes, and they start to recognize the patterns without counting, which is called subitizing. Then, they learn to produce the exact number of blocks you ask for. They recognize the largest of two quantities, increase the number of items they can count and learn more counting words. Variations in the rate of acquiring these skills may indicate potential future difficulties with mathematics.

Understanding Dyscalculia

A variety of diagnostic measures, cut-off criteria, and exclusion criteria are used to diagnose this learning disability. Research into dyscalculia has revealed several key characteristics:

1. Impaired intuitive understanding of numbers and their relationships, leading to difficulties with tasks such as counting up, counting down, quantity comparison, and recognizing shapes, sizes, and patterns.
2. Difficulties memorizing the basic math facts, with calculations, particularly with mental math, developing an internal number line (limited magnitude knowledge) and/or mathematical reasoning.
3. Performance one to two years below grade level.

Neuroimaging studies have revealed structural and functional differences in the brains of individuals with dyscalculia, particularly in regions associated with numerical magnitude processing, such as the intraparietal sulcus, which is the location of a quantity representation system that can both process small quantities exactly (subitizing) and approximate and compare larger quantities (using the Approximate Number system). This led to the assumption of a core neurological deficit. The triple code model emphasizes the importance of the intraparietal sulcus and occipitotemporal regions for symbol recognition (our written numerals), as well as the language network for number words and math terms. Recently, parallels have been found in the processing of magnitudes related to time, rhythm, and space, suggesting a more general magnitude system.

fMRI studies suggest that dyscalculia may result from deficits in multiple neurocognitive systems or their integration rather than a single localized issue. This complexity explains the varied manifestations of dyscalculia and its frequent co-occurrence with other learning disabilities, such as dyslexia and attention deficit disorder (ADD). Both domain-specific (quantity representation) and domain-general abilities (visual symbol retrieval, working memory, processing speed, verbal comprehension, and attention) contribute to mathematical competence.

Math Anxiety

The relationship between dyscalculia and math anxiety is complex and bidirectional. Students with dyscalculia may develop anxiety due to repeated failures, while anxiety itself can impair working memory, essential for problem-solving. This interaction can create a detrimental cycle of poor performance and increased anxiety.

Surprisingly, even mathematically proficient students may experience math anxiety, particularly when faced with time pressure. Research has shown that math anxiety can be "contagious," potentially transmitted by math-anxious parents, teachers, or peers. To mitigate this, it's crucial to emphasize the positive aspects of mathematics in everyday life and provide effective interventions to increase skills and understanding.

Intervention Methods

Early identification and intervention are critical, as numerous longitudinal studies have shown that students who enter early education with lower math skills often continue to struggle throughout elementary school without targeted support. While there is no one-size-fits-all approach to addressing dyscalculia, it is advised to adapt the intervention to the student's individual needs instead of following the grade curriculum and implementing it individually or in a small group. Key intervention strategies include:

1. Multisensory instruction: Utilizing visual, auditory, and kinesthetic approaches to reinforce mathematical concepts. This may involve manipulatives like blocks, dice, dominoes, and number lines.
2. Explicit instruction: Providing clear, direct instruction on mathematical skills and concepts, emphasizing reasoning and schema to minimize reliance on rote memory. Research favors structured sequential explicit instruction over project-based or discovery-based learning.
3. Balanced content: Combining training in basic arithmetic with problem-solving interventions.
4. Spaced learning: Gradually introducing new facts interspersed with facts that can already be retrieved from long-term memory.
5. Regular review: Consistently revisiting learned math facts and concepts to maintain active recall.
6. Cognitive training: Targeting specific cognitive skills such as working memory and attention through specialized programs or exercises. These programs may involve computer-based exercises or games and can train a specific skill, with limited evidence that this skill will generalize to other domains.
7. Accommodations and modifications: Adapting classroom practices to support students with dyscalculia, such as extended test time, use of math tools, graphic organizers, and assistive technology.

Tips for Parents

1. Early identification: Monitor your child's math progress and seek professional advice if struggles persist for six months or longer.
2. Encourage a growth mindset: Praise effort rather than results and emphasize that mistakes are part of the learning process.
3. Incorporate math into daily life: Use everyday situations to practice math skills in practical contexts. Cooking, shopping, and playing card games and board games with numbers provide opportunities to engage in math in a relaxed and fun way.
4. Utilize technology: Explore educational apps and games that make math engaging and interactive. These tools can provide additional practice and help reinforce concepts in an enjoyable way. Look for apps that provide suggestions when you make a mistake instead of apps that make a disapproving sound. A storyline with a funny character can make it more interesting.
5. Communicate with teachers: Share concerns about homework difficulties or math-related stress, and stay informed about your child's progress. Public schools have a process to document each student's progress and can arrange for a comprehensive assessment.
6. Seek professional assessment: Consider consulting a specialist for a comprehensive evaluation if struggles continue beyond 6 months.
7. Collaborate with the school: Maintain open communication with educators and share insights about effective strategies.

Advocacy and Future Directions

As awareness of dyscalculia grows, it's crucial for parents and educators to advocate for increased resources and support in schools. By highlighting the potential for progress through early intervention, we can inspire educational institutions to prioritize math support for students with dyscalculia. This collective effort can lead to more effective interventions, better-trained teachers, and ultimately, improved outcomes for students struggling with mathematics.

Conclusion

Developmental dyscalculia is a complex learning disability that requires a multifaceted approach to diagnosis, intervention, and support. Through increased awareness, early identification, and targeted interventions, we can help individuals with dyscalculia develop the mathematical skills necessary for academic and life success. By fostering a supportive environment that addresses both the cognitive and emotional aspects of mathematical learning, we can work towards a future where every child has the opportunity to reach their full potential in mathematics.

Dr Anneke M Schreuder

Dr. Anneke Schreuder, MD, is a Dutch-born pediatrician and neonatologist with extensive expertise in developmental epidemiology. Her professional journey took an unexpected turn when her daughter was diagnosed with dyslexia, leading Dr Schreuder to delve deeper into the field of learning disabilities.

For several years, Dr. Schreuder served as a dyslexia tester and tutor at the University of Texas Health Science Center. Observing the prevalence of math-related struggles among students, she decided to refocus on her area of expertise and passion: mathematics. In 2010, she founded Dyscalculia Services, an organization dedicated to providing comprehensive support for individuals with dyscalculia.

Dr. Schreuder's professional interests extend to neuroimaging and neurodevelopmental pediatrics, with a particular focus on their relationship to early childhood development and education. Her commitment to advancing the field is evident through her various professional affiliations and contributions:

• Board member of the Learning Disabilities Association of Texas
• Co-chair of the Professional Advisory Board for the Learning Disabilities Association of America
• Frequent speaker on dyscalculia at national and international conferences
• Consultant to various educational institutions
• Developer of a series of online courses for training dyscalculia tutors

Extracts from Dystinct Magazine