Human Motor Control - effects of exercise on nervous system function
| Our research interests lie in determining how the central nervous system is reorganised as a consequence of motor learning and exercise. Our work is funded by the Australian Research Council (ARC), and we have a specific interest in the area of resistance training (or weight lifting exercise). We use electro-physiological techniques such as Transcranial Magnetic Stimulation (TMS), peripheral nerve stimulation, and electromyography (EMG) in experiments involving human subjects. The ultimate purpose is to generate fundamental knowledge that will lead to the incorporation of resistance training protocols that yield maximal benefits into programs of rehabilitation and injury prevention. | |
Current Projects
Functional organisation of spinal circuits projecting to the human wrist
| As a first step towards understanding how exercise affects the efficacy of specific circuits in the spinal cord, we are conducting experiments to establish how these circuits operate during a range of functional tasks. More specifically, we are assessing the task-dependent modulation of transmission through the neural pathways involved in disynaptic 1a reciprocal inhibition, autogenic recurrent inhibition and presynaptic inhibition of the 1a afferent- motoneuronal synapse. | |
The impact of resistance training on sensori-motor coordination
| We have previously shown that resistance training can improve the ability to perform complicated tasks that require timing movements with sensory events (such as an auditory pacing signal). We aim to establish the mechanism for this improvement by assessing the how resistance training involving specific patterns of muscle recruitment influences performance on carefully chosen coordination tasks. This information will be critical in determining the practical utility of resistance training in many rehabilitation contexts. | |
The effects of resistance training on CNS organisation
| We are using peripheral nerve stimulation and TMS to assess how resistance training affects the function of specific circuits in the brain and spinal cord. By measuring the reflex responses to electrical stimulation of nerves and how these responses are modulated by descending and segmental influences, we can determine the functional efficacy of specific neural pathways before and after resistance training. | |
Staff and Students
Dr Tim Carroll
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Michael Lee (PhD Student)
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Marlene Hsu (Research Assistant) | 
Justin Barton (Honours Student) |
Collaborators
Professor Simon Gandevia (Prince of Wales Medical Research Institute, Sydney)
Professor Richard Carson (University of Queensland, Brisbane)
Dr Paul Zehr (University of Victoria, Canada)
Dr David Collins (University of Alberta, Canada)
Assoc Professor Steve Boutcher (UNSW)
Research Support
Our work is currently supported by an ARC Discovery Grant (2004-2006) and has also received support from the NHMRC (Equipment Grant, 2004).
Selected Publications
Lee M,
Carroll TJ (In Press) The amplitude of Mmax in human wrist flexors varies during different muscle contractions despite constant posture.
Journal of Neuroscience Methods.
Carroll TJ, Baldwin ERL, Collins DF. (2005). Task dependent gain regulation of spinal circuits projecting to the human flexor carpi radialis.
Experimental Brain Research. 161(3): 299-306.
Zehr EP,
Carroll TJ, Chua R, Collins DF, Frigon A, Haridas C, Hundza SR, Kido A. (2004). Possible contributions of CPG activity to the control of rhythmic arm movement.
Canadian Journal of Physiology and Pharmacology. 82(8-9): 556-568.
Carroll TJ, Zehr EP, Collins DF. (2004). Modulation of cutaneous reflexes in human upper limb muscles during arm cycling is independent of activity in the contralateral arm.
Experimental Brain Research. 161(2): 133-44.
Carroll TJ, Riek S, Carson RG. (2002) The sites of neural adaptation induced by resistance training in humans.
The Journal of Physiology, 544: 641-652.
Carroll TJ, Barry B, Riek S, Carson RG. (2001) Resistance training enhances the stability of sensori-motor coordination.
The Proceedings of the Royal Society of London B. 268: 221-227.
Carroll TJ, Riek S, Carson RG. (2001) Cortico-spinal responses to motor training revealed by transcranial magnetic stimulation.
Exercise and Sport Sciences Reviews. 29(2): 54-59.
Carroll TJ, Riek S, Carson RG. (2001) Neural adaptations to resistance training: Implications for movement control.
Sports Medicine. 31(12):829-840.
Carroll TJ, Riek S, Carson RG. (2001) Reliability of the input-output properties of the corticospinal pathway obtained from transcranial magnetic and electrical stimulation.
Journal of Neuroscience Methods, 112(2):193-202.