title: Diminished time-based, but undiminished event-based, prospective memory among intellectually high-functioning adults with autism spectrum disorder: relation to working memory ability.
abstract: OBJECTIVE
  Prospective memory (PM) is the ability to remember to carry out an intended action. Working memory is the ability to store information in mind while processing potentially distracting information. The few previous studies of PM in autism spectrum disorder (ASD) have yielded inconsistent findings. Studies of working memory ability in ASD have suggested a selective impairment of "visual working memory." However, it remains unclear whether any such impairment is the result of diminished (domain-specific; visual/verbal) storage capacity or diminished (domain-general) processing capacity. We aim to clarify these issues and explore the relation between PM and working memory in ASD.
  
  
  METHODS
  Seventeen adults with ASD and 17 age- and IQ-matched comparison participants completed experimental measures of both event-based (perform action x when event y occurs) and time-based (perform action a at time b) PM, plus a self-report measure of PM skills. Participants also completed a working memory test battery.
  
  
  RESULTS
  Participants with ASD self-reported diminished PM skill, and showed diminished performance on the time-based, but not event-based, PM task. On the working memory test battery, visual but not verbal storage capacity was diminished among participants with ASD, as was processing ability. Whereas visual storage was associated with event-based PM task performance among comparison participants, verbal storage was associated among ASD participants.
  
  
  CONCLUSIONS
  ASD appears to involve a selective deficit in time-based PM and a selective difficulty with aspects of working memory that depend on the storage of visual information. However, event-based PM may be achieved through compensatory strategies in ASD.
authors.affiliation: Department of Psychology, Durham University.
authors.forename: David M
authors.initials: DM
authors.lastname: Williams
authors.affiliation: School of Experimental Psychology, University of Bristol.
authors.forename: Christopher
authors.initials: C
authors.lastname: Jarrold
authors.affiliation: Department of Psychology, Durham University.
authors.forename: Catherine
authors.initials: C
authors.lastname: Grainger
authors.affiliation: Department of Psychology, Durham University.
authors.forename: Sophie E
authors.initials: SE
authors.lastname: Lind
mesh_terms: D000328:Adult; D002659:Child Development Disorders, Pervasive / Q000523:psychology*; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D061212:Memory, Episodic; D008570:Memory, Short-Term; D013997:Time Factors