Learning disabilities are roughly divided along three lines; reading, writing, and arithmetic. Each of these Learning Disorders, formerly “Academic Skills Disorders”, may be diagnosed in isolation or in combination with other learning problems.
It is important for the public to understand the process by how these disorders are diagnosed. Initially the patient is given a test to determine their Full Scale intelligence quotient. These tests typically require 1.5 to 3.0 hours to administer. The patient is then administered tests of achievement. These tests measure core academic skills in relation to others their own age. Once the scores are tabulated and normalized, the psychologist compares the Full Scale IQ to each achievement subtest in reading, writing, and math. If there is more than one standard deviation difference between their IQ and an achievement score, the psychologist may diagnose that patient with a specific learning disorder.
One standard deviation implies that the observed spread between the scores could not readily happen by chance alone, or at least less than a one-in-twenty chance of being purely random. If the psychologist places their faith on 1.5 to 2.0 standard deviations, than there is an even smaller chance that the observed discrepancy between scores is chance alone. The diagnostic manual for our field does not stipulate the exact statistical spread between scores, such that there is some room for interpretation-and error.
Most children and adults with learning disabilities cluster around math and reading/writing deficits. It is rare that there is a significant difference between reading and writing scores, but it is common to have significant differences between language and math scores. Reading and writing skills are neuropsychologically well correlated.
Most math deficits in children stem from visual-spatial difficulties, and most language errors from phonetic deficits. Often children who can’t sound out a word are very slow to learn in the early grades, but rapidly attain normal reading when sight reading strategies emerge by the third grade. Sight reading strategies depend heavily on visual-spatial skills, which circumvents the phonetic disability. Children with good phonetics often progress rapidly in reading and writing in the early grades, but slow significantly at math and sight reading strategies by the third grade. The emerging learning disability is typically visual-spatial in nature. Native readers of Chinese pictographs become aware of visual-spatial deficits at the start of reading and writing instruction. Unfortunately, some Learning Disorders are a mixed type, having both visual-spatial and phonetic deficits.
Treatment of Learning Disorders are generally accomplished with a plan that bridges the school into the home. Neuropsychological remediation focuses more on the cognitive strengths than the rehabilitation of deficits. After the age of 12, these Learning Disorder deficits tend to be lifelong. Prior to age 12, IQ tends to be very unstable. Many children who exhibit skill deficits at 8 years of age score as normal by 12 years of age. This typically happens without any neuropsychological intervention. If an adult or older child continues to experience problems with one or more academic areas, yet possess an Average IQ, then it is likely the deficit(s) will persist throughout their lifetime. Targeted neuropsychological intervention can minimize the impact of the deficit(s), but be confidant that the remedial work is long and difficult. Please leave your comments in the space provided below.