title: Time perception, phonological skills and executive function in children with dyslexia and/or ADHD symptoms.
abstract: BACKGROUND
  Deficits in time perception (the ability to judge the duration of time intervals) have been found in children with both attention-deficit/hyperactivity disorder (ADHD) and dyslexia. This paper investigates time perception, phonological skills and executive functions in children with dyslexia and/or ADHD symptoms (AS).
  
  
  METHODS
  Children with dyslexia-only (n = 17), AS-only (n = 17), comorbid dyslexia+AS (n = 25), and typically developing controls (n = 42), matched for age and non-verbal ability, were assessed on measures of phonological skills, executive function and time perception (duration discrimination and time reproduction).
  
  
  RESULTS
  Children with dyslexia were impaired on measures of phonological skill and duration discrimination compared to children without dyslexia (though problems on duration discrimination appeared to be attributable to mild symptoms of inattention in this group). In contrast, children with AS exhibited impairments on measures of both time perception and executive function compared to children without AS. Children with dyslexia+AS showed an additive combination of the deficits associated with dyslexia-only and AS-only.
  
  
  CONCLUSIONS
  Dyslexia and AS appear to be associated with distinct patterns of cognitive deficit, which are present in combination in children with dyslexia+AS.
authors.affiliation: Department of Psychology, University of York, Heslington, York, UK. d.gooch@psych.york.ac.uk
authors.forename: Debbie
authors.initials: D
authors.lastname: Gooch
authors.forename: Margaret
authors.initials: M
authors.lastname: Snowling
authors.forename: Charles
authors.initials: C
authors.lastname: Hulme
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000523:psychology*; D016022:Case-Control Studies; D002648:Child; D015897:Comorbidity; D004410:Dyslexia / Q000523:psychology*; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010700:Phonetics; D011932:Reading; D013998:Time Perception; D014706:Verbal Learning