title: Reach tracking reveals dissociable processes underlying inhibitory control in 5- to 10-year-olds and adults.
abstract: Researchers have proposed that two processes featuring distinct types of inhibition support inhibitory control: a response threshold adjustment process involving the global inhibition of motor output and a conflict resolution process involving competitive inhibition among co-active response alternatives. To target the development of these processes, we measured the reaching behavior of 5- to 10-year-olds (Experiment 1) and adults (Experiment 2) as they performed an Eriksen flanker task. This method provided two key measures: initiation time (the time elapsed between stimulus onset and movement onset) and reach curvature (the degree to which a movement deviates from a direct path to the selected target). We suggest that initiation time reflects the response threshold adjustment process by indexing the degree of motoric stopping experienced before a movement is started, while reach curvature reflects the conflict resolution process by indexing the degree of co-activation between response alternatives over the course of a movement. Our results support this claim, revealing different patterns effects in initiation time and curvature, and divergent developmental trajectories between childhood and adulthood. These findings provide behavioral evidence for the dissociation between global and competitive inhibition, and offer new insight into the development of inhibitory control.
authors.affiliation: Department of Psychology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Erb
authors.affiliation: Psychology Department, Williams College, Williamstown, Massachusetts, USA.|Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, Rhode Island, USA.
authors.forename: Jeff
authors.initials: J
authors.lastname: Moher
authors.affiliation: Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, Rhode Island, USA.|Brown Institute for Brain Science, Brown University, Rhode Island, USA.
authors.forename: Joo-Hyun
authors.initials: JH
authors.lastname: Song
authors.affiliation: Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, Rhode Island, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Sobel
mesh_terms: D000328:Adult; D002648:Child; D002657:Child Development / Q000502:physiology; D002675:Child, Preschool; D003071:Cognition / Q000502:physiology; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D009068:Movement / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*