title: Perception-action coupling in children with and without DCD: Frequency locking between task-relevant auditory signals and motor responses in a dual-motor task.
abstract: BACKGROUND
  The current research examines the relationship between perceptual and motor processes, known as perception-action or sensorimotor coupling, and the potential differences in perception-action coupling among children with and without Developmental Coordination Disorder (DCD) and adults in a gross-motor co-ordination task (clapping while marching) when a task-relevant driving sensory signal is present.
  
  
  METHODS
  Ten children with DCD (7.32 + 0.23 years), eight typically developing (TD) children who were age-, gender- and racially/ethnically matched (6.91 + 0.24 years) and 10 college-aged adults were participants in this study. Participants clapped and marched to an auditory beat at four different frequencies: 0.8, 1.2,1.6 and 2.0 Hz. The relative timing measures of mean relative phase (MRP) and variability of relative phase (VRP) were calculated and compared using 3 (group) x 4 (frequency) x 2 (limb) anovas. Qualitatively, participants were assessed for the presence of absolute coupling (100% + 15% MRP).
  
  
  RESULTS
  Statistically significant differences in MRP occurred for coupling, frequency and group, and post hoc analysis indicated that the adult group differed from both the DCD and TD groups, who did not differ from each other. In VRP, there were significant main effects for coupling and group, and a significant interaction between group and frequency, with post hoc analysis indicating the DCD group to be different from the TD and adult groups. Qualitatively, both the adult and TD groups increased in the number of participants who adopt absolute coupling as frequency increases. In contrast, the DCD participants adopt this absolute coupling far less frequently overall; in fact, the number of participants adopting this pattern decreases as frequency increases.
  
  
  CONCLUSIONS
  These results indicate that children with DCD have difficulties with both the co-ordination and the control of their perception-action coupling for this particular task.
authors.affiliation: University of Maryland-Baltimore, Baltimore, MD, USA.
authors.forename: J
authors.initials: J
authors.lastname: Whitall
authors.forename: N
authors.initials: N
authors.lastname: Getchell
authors.forename: S
authors.initials: S
authors.lastname: McMenamin
authors.forename: C
authors.initials: C
authors.lastname: Horn
authors.forename: A
authors.initials: A
authors.lastname: Wilms-Floet
authors.forename: J E
authors.initials: JE
authors.lastname: Clark
mesh_terms: D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D002648:Child; D005260:Female; D006801:Humans; D035002:Lower Extremity; D008297:Male; D019957:Motor Skills Disorders / Q000503:physiopathology*; D009068:Movement / Q000502:physiology*; D011597:Psychomotor Performance; D011930:Reaction Time; D034941:Upper Extremity