title: Effects of intentional movement preparation on response times to symbolic and imitative cues.
abstract: Speeded responses to an external cue are slower when the cue interrupts preparation to perform the same or a similar action in a self-paced manner. To explore the mechanism underlying this 'cost of intention', we examined whether the size of the cost is influenced by the nature of the external cue. Specifically, we assessed whether the cost of intention is different for movements made in response to an imitative cue (an on-screen hand movement) compared to those made in response to a symbolic cue. Consistent with previous reports, externally cued responses were significantly slower on trials where participants were preparing to perform an internally driven movement later in the trial. Also as predicted, simple response times to the imitative cue were faster than those made to the symbolic cue. Critically, the cost of intention was similar for each cue type, suggesting that preparing an intentional action influenced responses cued by the symbolic and imitative cues to a similar degree. These findings suggest that the nature of the external cue does not influence the response time delay associated with concurrent intentional preparation. Together with previous findings, the results of the current study shed further light on the potential mechanisms underlying the cost of intention.
authors.affiliation: Social Brain, Body and Action Lab, Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, ON, L8S 4L8, Canada. naishek@mcmaster.ca.
authors.forename: Katherine R
authors.initials: KR
authors.lastname: Naish
authors.affiliation: Social Brain, Body and Action Lab, Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, ON, L8S 4L8, Canada.
authors.forename: Amentha
authors.initials: A
authors.lastname: Rajagobal
authors.affiliation: Social Brain, Body and Action Lab, Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, ON, L8S 4L8, Canada.
authors.forename: Carl Michael
authors.initials: CM
authors.lastname: Galang
authors.affiliation: Dipartimento di Psicologia Generale, Universita di Padova, Padua, Italy.|Center for Cognitive Neuroscience, Universita di Padova, Padua, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Sartori
authors.affiliation: Social Brain, Body and Action Lab, Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, ON, L8S 4L8, Canada.
authors.forename: Sukhvinder S
authors.initials: SS
authors.lastname: Obhi
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D003463:Cues; D005260:Female; D006801:Humans; D007100:Imitative Behavior; D033182:Intention; D008297:Male; D009068:Movement / Q000502:physiology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology*; D013561:Symbolism; D013997:Time Factors; D055815:Young Adult
keywords: Externally triggered movements; Internally generated movement; Mirror neuron system; Motor preparation; Truncation