Lesser Known Disorders
Each issue of this series contains at least three lesser known disorders. Some of these disorders may contain subtypes which will also be presented. You will also notice that each disorder has a code. These codes represent the coding system for all disabilities and disorders listed in the Educator’s Diagnostic Manual(EDM) Wiley Publications.
Disorders in this issue:
LD 2.04-Developmental Anarithmetria Dyscalculia
Disability Category – Specific Learning Disabilities
Definition
This disability involves confusion with arithmetic procedures such as mixing addition, subtraction, multiplication, and other written operations (Yisrael, 2000).
Explanation
Students with Developmental Anarithmetria will use the incorrect operations when performing math problems. For example, the student states that 5 + 2 = 3. Here, the student performs the operation of subtraction instead of addition. Another example would be the student who states that 30 x 5 = 6. Again, an incorrect operation is performed (the student divided 30 by 5 instead of multiplying the numbers)
AU 8.00-Savant Syndrome Definition
Disability Category – Autism
Definition
An individual with ‘Autistic savant’ is one who is characterized by having a special skill. ‘Savant’ comes from the French word for ‘knowing’ and means ‘a learned person’. A person with this condition was once known as an ‘idiot savant’, since ‘idiot’ was an acceptable word for mental retardation in the late 19th century, when the phenomenon was first medically investigated. Around 10 per cent of people with autism show special or even remarkable skills. For example, a person with autism, who may be intellectually disabled in most ways, could have an exceptional memory for numbers (Autism Victoria, 2005).
Diagnostic Symptoms
According to the Autistic Society (2005) Particularly striking is the consistent observation also over this past century that savant skills typically, and curiously, are generally confined to only about five general areas of expertise—music, art, lightning calculating or other mathematical skills, calendar calculating and mechanical/spatial skills. These limited but special skills is noteworthy considering the much wider palette of skills in the human repertoire, and the rarity of the obscure skill of calendar calculating in the general population, which seems an ability almost universal, innately so, among savants.
Music is the generally the most common savant skill-usually playing piano by ear and almost always with perfect pitch. Other percussion instruments such as marimba or drums can be mastered as well, but much less frequently. Musical performance abilities predominate, but outstanding composing skills have been documented as well, most often linked to performance ability, but not necessarily so. The triad of mental disability, blindness and musical genius occurs with a curious, conspicuous frequency in reports over this past century, particularly when one considers the relative rarity of each of those circumstances individually.
Artistic talent, usually painting or drawing, is seen next most frequently. Other forms of artistic talent can occur as well, such as sculpting. Lightning calculating or other mathematical skills, such as the ability to compute multi-digit prime numbers contrasted with the inability to perform even simple arithmetic, has often been reported. Mechanical ability, constructing or repairing intricate machines or motors for example, or spatial skills such as intricate map and route memorizing, or being able to compute distances with precise accuracy just from visualization, do occur, but are seen somewhat less frequently.
Calendar calculating is curiously and conspicuously common among savants, particularly considering the rarity of that obscure skill in the general population. Beyond being able to name the day of the week that a date will occur on in any particular year, calendar calculating includes being able to name all the years in the next 100 in which Easter will fall on March 23rd, for example, or all the years in the next 20 when July 4 will fall on a Tuesday. The so-called ‘calculating twins’ reported extensively in the literature, have a calendar calculating span of over 40000 years backward or forward in time. They also remember the weather for every day of their adult life.
Other skills are occasionally seen including multilingual acquisition ability or other unusual language (polyglot) skills, exquisite sensory discrimination in smell or touch, perfect appreciation of passing time without access to a clock face, or outstanding knowledge in specific fields such as neurophysiology, statistics, history or navigation, to name a few. While always controversial, there have been some reports of extra-sensory perception skills occurring in savants as well.
Further Key Points
Approximately one in ten (10%) of persons with autistic disorder have some savant skills. In other forms of development disability, mental retardation or brain injury, savant skills occur in less than 1% of such persons (approximately 1:2000 in persons with mental retardation). Since these other forms of mental disability are much more common than autistic disorder however, it turns out that approximately 50% of persons with savant syndrome have autistic disorder, and the other 50% have some other form of developmental disability, mental retardation or brain injury or disease. Thus not all savants are autistic, and not all autistic persons are savants (Wisconsin Medical Society, 2005).
Savant skills occur within a narrow but constant range of human mental functions, generally in six areas: calendar calculating; lightening calculating & mathematical ability; art (drawing or sculpting); music (usually piano with perfect pitch); mechanical abilities; and spatial skills. In some instances unusual language abilities have been reported but those are rare. Other skills much less frequently reported include map memorizing, visual measurement, extrasensory perception, unusual sensory discrimination such as enhanced sense of touch & smell, and perfect appreciation passing time without knowledge of a clock face. The most common savant skill is musical ability (Autism Today, 2005).
SL 2.04-Addition Articulation Disorder
Disability Category – Speech and Language Impairment
Definition
A type of articulation disorder associated with errors in the formation of individual speech sounds whereby additional and incorrect letters are added to words (Marshall University, 2005).
Explanation
Addition articulation errors occur when a sound (s) is added by the individual to a word. Examples include saying:
- galue for glue
- happity for happy
- televelephone for telephone
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