title: Bidirectional Interference Between Speech and Nonspeech Tasks in Younger, Middle-Aged, and Older Adults.
abstract: OBJECTIVE
  The purpose of this study was to examine divided attention over a large age range by looking at the effects of 3 nonspeech tasks on concurrent speech motor performance. The nonspeech tasks were designed to facilitate measurement of bidirectional interference, allowing examination of their sensitivity to speech activity. A cross-sectional design was selected to explore possible changes in divided-attention effects associated with age.
  
  
  METHODS
  Sixty healthy participants were separated into 3 groups of 20: younger (20s), middle-aged (40s), and older (60s) adults. Each participant completed a speech task (sentence repetitions) once in isolation and once concurrently with each of 3 nonspeech tasks: a semantic-decision linguistic task, a quantitative-comparison cognitive task, and a manual motor task. The nonspeech tasks were also performed in isolation.
  
  
  RESULTS
  Data from speech kinematics and nonspeech task performance indicated significant task-specific divided attention interference, with divided attention affecting speech and nonspeech measures in the linguistic and cognitive conditions and affecting speech measures in the manual motor condition. There was also a significant age effect for utterance duration.
  
  
  CONCLUSIONS
  The results increase what is known about bidirectional interference between speech and other concurrent tasks as well as age effects on speech motor control.
authors.forename: Dallin J
authors.initials: DJ
authors.lastname: Bailey
authors.forename: Christopher
authors.initials: C
authors.lastname: Dromey
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology / Q000523:psychology; D001288:Attention; D001696:Biomechanical Phenomena; D003071:Cognition; D005260:Female; D006225:Hand / Q000502:physiology; D006801:Humans; D007807:Language Tests; D008046:Lip / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011581:Psychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D012660:Semantics; D012727:Sex Characteristics; D013060:Speech / Q000502:physiology; D013997:Time Factors; D055815:Young Adult