title: Observing object lifting errors modulates cortico-spinal excitability and improves object lifting performance.
abstract: Observing the actions of others has been shown to modulate cortico-spinal excitability and affect behaviour. However, the sensorimotor consequences of observing errors are not well understood. Here, participants watched actors lift identically weighted large and small cubes which typically elicit expectation-based fingertip force errors. One group of participants observed the standard overestimation and underestimation-style errors that characterise early lifts with these cubes (Error video--EV). Another group watched the same actors performing the well-adapted error-free lifts that characterise later, well-practiced lifts with these cubes (No error video--NEV). We then examined actual object lifting performance in the subjects who watched the EV and NEV. Despite having similar cognitive expectations and perceptions of heaviness, the group that watched novice lifters making errors themselves made fewer overestimation-style errors than those who watched the expert lifts. To determine how the observation of errors alters cortico-spinal excitability, we measured motor evoked potentials in separate group of participants while they passively observed these EV and NEV. Here, we noted a novel size-based modulation of cortico-spinal excitability when observing the expert lifts, which was eradicated when watching errors. Together, these findings suggest that individuals' sensorimotor systems are sensitive to the subtle visual differences between observing novice and expert performance.
authors: Department of Psychology, School of Life Sciences, Heriot-Watt University, Edinburgh, UK; The Brain and Mind Institute, The University of Western Ontario, Canada. Electronic address: g.buckingham@hw.ac.uk.
authors: Gavin
authors: G
authors: Buckingham
authors: The Brain and Mind Institute, The University of Western Ontario, Canada; The Department of Psychology, The University of Western Ontario, Canada; The Graduate Program in Neuroscience, The University of Western Ontario, Canada.
authors: Jeremy D
authors: JD
authors: Wong
authors: The Department of Physiology and Pharmacology, The University of Western Ontario, Canada.
authors: Minnie
authors: M
authors: Tang
authors: The Brain and Mind Institute, The University of Western Ontario, Canada; The Department of Psychology, The University of Western Ontario, Canada; The Department of Physiology and Pharmacology, The University of Western Ontario, Canada.
authors: Paul L
authors: PL
authors: Gribble
authors: The Brain and Mind Institute, The University of Western Ontario, Canada; The Department of Psychology, The University of Western Ontario, Canada.
authors: Melvyn A
authors: MA
authors: Goodale
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology; D000328:Adult; D003463:Cues; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D005385:Fingers / Q000502:physiology; D006801:Humans; D007088:Illusions; D007858:Learning; D017770:Lifting; D008297:Male; D019370:Observation; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology*; D011712:Pyramidal Tracts / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation
keywords: Action observation; Grip force error; Motor learning; Object lifting; Size-weight illusion