Definitions and Characteristics of Dyslexia
Dyslexia may be defined as the failure to develop specific perceptual motor skills to expected proficiency independent of instruction, motivation, sense organ functioning, intelligence and CNS damage. That it qualifies as specific is indicated by the discrepancy between achievement in certain activities as compared to achievement in other activities. It is not a disease, but an arrestation of anticipated development.
These discrepancies in the development of perceptual motor skills may be summarized as follows. (Shedd 1967):
- Spotty performance on IQ test; achievement is high in some areas, low in others.
- Below mental age on tests of drawing a person.
- Visual motor Gestalt test are poor for age and indicated intelligence.
- Poor performance on group tests which require reading and writing.
- Impaired orientation in time.
- Impaired discrimination of right and left.
- Poor spatial orientation.
- Field dependent perception.
- Frequent perceptual reversals in reading and writing numbers beyond age and instruction level.
- Impaired reproduction of rhythmic pattern.
- Impaired reproduction of tonal patterns.
- Impaired discrimination of auditory stimuli.
- Frequent mild speech irregularities.
- Non-specific motor awkwardness.
- A periodic loss of fine motor skills.
- Reading disabilities.
- Spelling disabilities.
- Writing disabilities.
- Variability in performance.
- Poor ability to organize work.
- Slowness in finishing work.
- Short attention span for age.
- Impaired concentration ability.
All of these characteristics must be present, or there must be evidence that they were present prior to remediation, before a diagnosis of dyslexia can be given. The existence of the characteristics in contiguity is terribly important, for some of the characteristics related to other diagnostic entities and may even be present in a normal person. If a generalization was made relative to the common characteristics of all these discrepancies, it would appear that there is a lack of organizational facility.