Understanding the complexities of Hyperlexia and its Subtypes
Hyperlexia has often been treated as a form of reading disorder manifested by an unexpected superior ability to read fluently but an equally unexpected deficit in reading/listening comprehension (Chia, 1995). It is often categorized as a subtype of dyslexia, also known as direct dyslexia. In order to differentiate between the two conditions, it is important for us to look at the profile of a reader and then the process of reading/listening comprehension,
Chia (1998) has outlined 4 different profiles of reader, namely, (1) the independent reader, (2) the reluctant (sometimes also known as struggling) reader, (3) the disabled reader, and (4) the illiterate. It is the third category that I am interested.
As can be read in Aaron (1989) and Chia (1998, 2001), disabled readers can be subdivided into three other sub-categories: (1) dyslexic, (2) hyperlexic, and (3) the non-specific reading disabled. Hyperlexia is seen as falling in one extreme end of a continuum of reading disabilities, while dyslexia is on the other extreme end. In between the continuum are the various reading-related anomalies. As already mentioned earlier, hyperlexia is a developmental disorder characterized by a good ability to decode and read words way ahead what would be expected of a child at his/her chronological age but a significant lack of comprehension in what has been read as well as understanding verbal language (i.e., listening comprehension). Generally, hyperlexic readers often display the following symptoms: (1) need to re-read text a few times and often remember only a few details, rather than the “whole”; (2) written language is often unorganized and non-specific; (3) has difficulty socializing and interacting appropriately with others; and (4) has difficulty following conversation and tends to repeat questions (echolalic) and often known to be “poor listener” (Quah, 2002).
Comprehension is a process involving the ability to encode or decode letters and sounds into meaningful words, connecting meanings in context and interrelated sentences to form an overall cohesive and coherent text. Prior acquired knowledge and experience are also essential in assisting establishment of meaningful reading. Comprehension is thus an interactive process that goes beyond mere reading. Hyperlexic readers are unable to make these connections although they have good phonological and orthographic ability and rote memory. Hyperlexic readers not only have reading comprehension difficulties, but also lacking in critical thinking skills (Chia, 2007), following directions, following conversational speech and difficulty expressing ideas in an orderly manner.
In view of these problems, hyperlexia has been seen as an overlap between autism and language learning disorder forming what is known as Hyperlexia Type 1, and between visual-spatial perceptual disorder and Asperger syndrome forming what is known as Hyperlexia Type 2 (Richman, 1994). Chia (2003) has subcategorized further into Hyperlexia Subtypes 1A and 1B, and Hyperlexia Subtypes 2A and 2B. He added that there is yet a third type, Hyperlexia Type 3 which can be subdivided into Hyperlexia Subtype 3A (Direct Dyslexia) and Hyperlexia Subtype 3B (Non-verbal Learning Disorder, also known as Reversed Dyslexia).
In diagnosing children suspected of having hyperlexia, it is important to assess such children in the context of suspected pervasive developmental disorder (including autism spectrum disorder and non-autistic disorders such as Rett’s syndrome). It is also important to take into consideration of semantic-pragmatic disorder (SPD for short, and sometimes known as high-functioning autism disorder or HFAD for short, although experts are still divided about the condition) which coincides with autism spectrum disorder (i.e., early infantile autism) forming what Chia (2007) named as the possibility of the existence of Hyperlexia Type 1.ii which can be subdivided into Hyperlexia Subtype 1.i.A (i.e., Hyperlexic-Language Learning Disorder), Hyperlexia Subtype 1.i.B (i.e., Hyperlexia with ASD) and Hyperlexia Subtype 1.ii.A (i.e., Hyperlexia with SPD).
Finally, in planning treatment for children diagnosed with hyperlexia, it is thus important to be precise with the diagnosis in order to select appropriate intervention strategies to work with such children.
This article is contributed by Ms Ruth Y.K. Leong, a special needs therapist registered with the International Association of Counselors & Therapists, USA.
Copyright © 2007 Ruth Y.K. Leong. All rights reserved. see Disclaimer