Learning Disabilities in Arithmetic and Mathematics Theoretical and Empirical Perspectives

The breadth and complexity of the field of mathematics make the identification and study of the cognitive phenotypes that define learning disabilities in mathematics (MD) a formidable endeavor. A learning disability can result from deficits in the ability to represent or process information in one or all of the many mathematical domains (e.g., geometry) or in one or a set of individual competencies within each domain. The goal is further complicated by the task of distinguishing poor achievement due to inadequate instruction from poor achievement due to an actual cognitive disability (Geary, Brown, & Samaranayake, 1991). One approach that can be used to circumvent this instructional confound involves is to apply the theories and methods used to study mathematical competencies in normal children to the study of children with a picture of the cognitive and brain systems that can contribute to MD begins to emerge. The combination of theoretical and empirical approaches has been primarily applied to the study of numerical and arithmetical competencies and is therefore only a first step to a complete understanding of the cognitive and brain systems that support mathematical compe-tency, and any associated learning disabilities. It is, nonetheless, a start. We overview what this research strategy has revealed about children with MD in the second section, and discuss diagnostic, prevalence, and etiological issues in the first section. In the third section, we present a general organizational framework for approaching the study of MD in any mathematical domain and use this framework and an earlier taxonomy of MD subtypes (Geary, 1993) to better understand the cognitive deficits described in the second section.