Hyperlexia

Hyperlexia is a syndrome characterized by a child's precocious ability to read. It was initially identified by Norman E. Silberberg and Margaret C. Silberberg (1967), who defined it as the precocious ability to read words without prior training in learning to read, typically before the age of five. They indicated that children with hyperlexia have a significantly higher word-decoding ability than their reading comprehension levels. Children with hyperlexia also present with an intense fascination for written material at a very early age. Hyperlexic children are characterized by word-reading ability well above what would be expected given their age. First named and scientifically described in 1967 (Silverberg and Silverberg), it can be viewed as a superability in which word recognition ability goes far above expected levels of skill. Some hyperlexics, however, have trouble understanding speech. Some experts believe that most children with hyperlexia, or perhaps even all of them, lie on the autism spectrum. However, one expert, Darold Treffert, proposes that hyperlexia has subtypes, only some of which overlap with autism. Between five and twenty percent of autistic children have been estimated to be hyperlexic. Hyperlexic children are often fascinated by letters or numbers. They are extremely good at decoding language and thus often become very early readers. Some English-speaking hyperlexic children learn to spell long words (such as elephant) before they are two years old and learn to read whole sentences before they turn three. The word hyperlexia is derived from the Greek terms hyper 'over, beyond, overmuch, above measure' and lexis 'word'. Although hyperlexic children usually learn to read in a non-communicative way, several studies have shown that they can acquire reading comprehension and communicative language after the onset of hyperlexia. They follow a different developmental trajectory relative to neurotypical individuals, with milestones being acquired in a different order.