title: Understanding conservation delays in children with specific language impairment: task representations revealed in speech and gesture.
abstract: OBJECTIVE
  The authors investigated mental representations of Piagetian conservation tasks in children with specific language impairment (SLI) and typically developing peers. Children with SLI have normal nonverbal intelligence; however, they exhibit difficulties in Piagetian conservation tasks. The authors tested the hypothesis that conservation difficulties may be due to the degree to which children with SLI rely on external perceptual features of the task as opposed to internal cognitive knowledge about transformation.
  
  
  METHODS
  Twenty-nine children participated, 12 children with SLI (ages 7;0-10;5) and 17 typically developing peers (ages 5;4-10;9) who were matched either on chronological age (CA) task or on judgments on the conservation task (conservation matched [CM]). Children solved conservation tasks and then explained their reasoning. Explanations produced in speech and gesture were analyzed.
  
  
  RESULTS
  In speech, children in the SLI group expressed proportionately fewer internal explanations than the CA group, but a similar proportion of internal explanations as compared with the younger CM group. In gesture, children with SLI did not differ from either CA or CM children.
  
  
  CONCLUSIONS
  Children with SLI have weak internal representations of the concept of conservation, similar to those of younger children. Conservation representations appear to be closely related to language skills and verbal working memory.
authors.affiliation: University of Iowa, Iowa City, USA. ezm3@psu.edu
authors.forename: Elina
authors.initials: E
authors.lastname: Mainela-Arnold
authors.forename: Julia L
authors.initials: JL
authors.lastname: Evans
authors.forename: Martha W
authors.initials: MW
authors.lastname: Alibali
mesh_terms: D002648:Child; D002675:Child, Preschool; D003071:Cognition; D005260:Female; D005868:Gestures; D006801:Humans; D007806:Language Disorders / Q000175:diagnosis*; D008297:Male; D009633:Nonverbal Communication; D013067:Speech Perception; D013068:Speech Production Measurement; D013997:Time Factors; D014706:Verbal Learning