Dyscalculia
[7][8] Dyscalculia does not reflect a general deficit in cognitive abilities or difficulties with time, measurement, and spatial reasoning.
[13] Mathematical disabilities can occur as the result of some types of brain injury, in which case the term acalculia is used instead of dyscalculia, which is of innate, genetic or developmental origin.
[citation needed] The earliest appearance of dyscalculia is typically a deficit in subitizing, the ability to know, from a brief glance and without counting, how many objects there are in a small group.
However, children with dyscalculia can subitize fewer objects and, even when correct, take longer to identify the number than their age-matched peers.
[21] Adults with dyscalculia may struggle with directions while driving and with controlling their finances, leading to difficulties on a day-to-day basis.
Yet, it does not rule out an impaired ability to access and manipulate numerical quantities from their symbolic representations (e.g., Arabic digits).
Moreover, findings from a cross-sectional study suggest that children with developmental dyscalculia might have a delayed development in their numerical magnitude representation by as much as five years.
[31] However, the lack of longitudinal studies still leaves the question open as to whether the deficient numerical magnitude representation is a delayed development or impairment.
[citation needed] Rousselle & Noël[32] propose that dyscalculia is caused by the inability to map preexisting representations of numerical magnitude onto symbolic Arabic digits.
[33] Neuroimaging studies also report increased activation in the right intraparietal sulcus during tasks that measure symbolic but not non-symbolic processing of numerical magnitude.
[36] Mathematics is a specific domain that is complex (i.e. includes many different processes, such as arithmetic, algebra, word problems, geometry, etc.)
[37] However, due to the cost and time limitations associated with brain and neural research, these methods will likely not be incorporated into diagnostic criteria despite their effectiveness.
[42][8] Whether a particular subtype is specifically termed "dyscalculia" as opposed to a more general mathematical learning disability is somewhat under debate in the scientific literature.
[53][54] A one-to-one tutoring paradigm designed by Lynn Fuchs and colleagues which teaches concepts in arithmetic, number concepts, counting, and number families using games, flash cards, and manipulables has proven successful in children with generalized math learning difficulties, but intervention has yet to be tested specifically on children with dyscalculia.
[55][56][57] These methods require specially trained teachers working directly with small groups or individual students.
For this reason, several research groups have developed computer adaptive training programs designed to target deficits unique to dyscalculic individuals.
Rescue Calcularis was one early computerized intervention that sought to improve the integrity of and access to the mental number line.
Butterworth and colleagues argued that games like The Number Bonds, which allows an individual to compare different sized rods, should be the direction that digital interventions move toward.
Based on these findings, Dybuster Calcularis was extended by adaptation algorithms and game forms allowing manipulation by the learners.
When the same research group used tDCS in a training study with two dyscalculic individuals, the reverse setup (left anodal, right cathodal) demonstrated improvement of numerical abilities.
His research proved that the learning disability was caused by impairments to certain parts of the brain that control mathematical calculations and not because symptomatic individuals were "mentally handicapped".
The term is often used to refer specifically to the inability to perform arithmetic operations, but is also defined by some educational professionals and cognitive psychologists such as Stanislas Dehaene[72] and Brian Butterworth[10] as a more fundamental inability to conceptualize numbers as abstract concepts of comparative quantities (a deficit in "number sense"), which these researchers consider to be a foundational skill upon which other mathematics abilities build.
