Learning Disabilities

Despite federal regulations, the definition of learning disabilities is controversial. The U.S. government defines a specific learning disability as a disorder in one or more of the basic psychological processes involved in understanding or use of spoken or written language, which may be manifest as an inability to listen, think, speak, read, write, spell, or do mathematic calculations. While the definition could include the conditions of perceptual handicaps, brain injury, minimal brain dysfunction, dyslexia, and developmental aphasia, it is not applicable to students whose learning problems are the result of visual, hearing, or motor handicaps, mental retardation, emotional disturbance, or environmental/cultural disadvantage. The major premise is that a significant discrepancy exists between the child's potential and her actual level of academic or language skills.

Each state, however, may determine cutoffs for discrepancies or definitions of processing disorders, leading to variability among states and even differences among districts within a given state. The definition and diagnosis of an LD vary, depending on whether the purpose is to qualify for services or to clinically identify the reason for a child's poor academic performance. In the former, measurement of intelligence and levels of achievement is employed; in the latter, administration of IQ and achievement is extended to include evaluation of attention, memory, and neuropsychological function. Moreover, the age of identification varies, depending on the type of LD; some may not be apparent early because academic skills in areas affected by the LD have not yet been challenged.

The psychiatric definition of LDs (as found in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders: DSM-IV) differs considerably from both federal and state classification systems, adding further to the ambiguity. Learning disabilities are presumed to be due to central nervous system dysfunction, and occur across the lifespan. They reportedly occur more in males, although research in the late 1990s by Sally Shaywitz has disputed this contention.