title: Looking before you leap: a theory of motivated control of action.
abstract: The acquisition of volitional control depends, in part, on developing the ability to countermand a planned action. Many tasks have been used to tap the efficiency of this process, but few studies have investigated how it may be modulated by participants' motivation. Multiple mechanisms may be involved in the deliberate exercise of caution when incentives are provided. For example, control may involve modulation of the efficiency of the countermanding process, and/or inhibitory modulation of the impulse to go. One of the most commonly used paradigms to assess control of action is the Stop Signal Task, in which a primary Go stimulus is occasionally followed by a countermanding Stop signal, allowing a Stop Signal Reaction Time (SSRT) to be inferred as the outcome of a "horse race" between the go and countermanding processes. Here, we present a computational model in which high task motivation modulates proactive pre-stimulus inhibition of the go response. This allows responses to be calibrated so as to fall within a time-window that maximizes the probability of success, regardless of trial type, but does not decrease the observed SSRT. We report empirical support for the model from a sample of typically developing children, and discuss the broader implications for operationalizing measures of volitional control.
authors.affiliation: University of Nottingham, School of Community Health Sciences, Division of Psychiatry, E Floor, South Block, Queen's Medical Centre, Derby Road, Nottingham NG72UH, UK. Elizabeth.Liddle@nottingham.ac.uk
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: Liddle
authors.forename: Gaia
authors.initials: G
authors.lastname: Scerif
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Hollis
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Batty
authors.forename: Madeleine J
authors.initials: MJ
authors.lastname: Groom
authors.forename: Mario
authors.initials: M
authors.lastname: Liotti
authors.forename: Peter F
authors.initials: PF
authors.lastname: Liddle
mesh_terms: D002648:Child; D002755:Choice Behavior / Q000502:physiology; D003198:Computer Simulation; D005260:Female; D006801:Humans; D008297:Male; D009042:Motivation; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time