A syndrome found in young children that resembles autism. It is characterized by a significant difficulty in understanding verbal language, and social interaction, but an ability to read words at a level far above what one would expect at their age. The sources I found on it gave no information on how it is caused, but I found a few symptoms:
  1. ritualistic behavior, and an obsessive need for routine
  2. strong visual memory and auditory memory.
  3. Difficulty with abstract concepts
  4. Difficulty answering who/what/when/where/why questions.
  5. Selective listening, and the appearance of being deaf
Children with hyperlexia tend to develop normally until they are 18-24 months old. An old boss of mine had a 6-year old hyperlexic child, who I met once. He seemed shy and withdrawn, and preoccupied with the office plants, to the extent of 'watering' one.

Hyperlexia is treated by taking the child to a therapist, who will help the child work out ways to fit in with other people. One therapist outlines nine major points of hyperlexia treatment:

  1. Use written and visual models.
  2. Use patterned language.
  3. Use open ended sentences.
  4. Generate Rules.
  5. Use examples rather than explanations.
  6. Use rote learning.
  7. Teach one way, then reverse the procedure.
  8. Teach specific pragmatic rules.
  9. Use parents a co-therapists.
If treatment goes well, hyperlexic children should be able to function as shy kindergarteners, and later as gifted students who are able to figure out their own ways to overcome or take advantage of their condition.

Thanks to www.hyperlexia.org for the info.