title: Autism-specific covariation in perceptual performances: "g" or "p" factor?
abstract: BACKGROUND
  Autistic perception is characterized by atypical and sometimes exceptional performance in several low- (e.g., discrimination) and mid-level (e.g., pattern matching) tasks in both visual and auditory domains. A factor that specifically affects perceptive abilities in autistic individuals should manifest as an autism-specific association between perceptual tasks. The first purpose of this study was to explore how perceptual performances are associated within or across processing levels and/or modalities. The second purpose was to determine if general intelligence, the major factor that accounts for covariation in task performances in non-autistic individuals, equally controls perceptual abilities in autistic individuals.
  
  
  METHODS
  We asked 46 autistic individuals and 46 typically developing controls to perform four tasks measuring low- or mid-level visual or auditory processing. Intelligence was measured with the Wechsler's Intelligence Scale (FSIQ) and Raven Progressive Matrices (RPM). We conducted linear regression models to compare task performances between groups and patterns of covariation between tasks. The addition of either Wechsler's FSIQ or RPM in the regression models controlled for the effects of intelligence.
  
  
  RESULTS
  In typically developing individuals, most perceptual tasks were associated with intelligence measured either by RPM or Wechsler FSIQ. The residual covariation between unimodal tasks, i.e. covariation not explained by intelligence, could be explained by a modality-specific factor. In the autistic group, residual covariation revealed the presence of a plurimodal factor specific to autism.
  
  
  CONCLUSIONS
  Autistic individuals show exceptional performance in some perceptual tasks. Here, we demonstrate the existence of specific, plurimodal covariation that does not dependent on general intelligence (or "g" factor). Instead, this residual covariation is accounted for by a common perceptual process (or "p" factor), which may drive perceptual abilities differently in autistic and non-autistic individuals.
authors.affiliation: The University of Montreal Center of Excellence for Pervasive Developmental Disorders (CETEDUM), Hôpital Rivière-des-Prairies, Montreal, Quebec, Canada.
authors.forename: Andrée-Anne S
authors.initials: AA
authors.lastname: Meilleur
authors.affiliation: The University of Montreal Center of Excellence for Pervasive Developmental Disorders (CETEDUM), Hôpital Rivière-des-Prairies, Montreal, Quebec, Canada.
authors.forename: Claude
authors.initials: C
authors.lastname: Berthiaume
authors.affiliation: The University of Montreal Center of Excellence for Pervasive Developmental Disorders (CETEDUM), Hôpital Rivière-des-Prairies, Montreal, Quebec, Canada; School/Applied Child Psychology, Department of Education and Counselling Psychology, McGill University, Montreal, Quebec, Canada.
authors.forename: Armando
authors.initials: A
authors.lastname: Bertone
authors.affiliation: The University of Montreal Center of Excellence for Pervasive Developmental Disorders (CETEDUM), Hôpital Rivière-des-Prairies, Montreal, Quebec, Canada.
authors.forename: Laurent
authors.initials: L
authors.lastname: Mottron
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001321:Autistic Disorder / Q000175:diagnosis* / Q000523:psychology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D010465:Perception; D010775:Photic Stimulation; D013647:Task Performance and Analysis; D055815:Young Adult