Postural adjustments as an acquired motor skill: Delayed gains and robust retention after a single training session within a virtual environment

Postural adjustments are essential for voluntary movement as they provide the foundation for motor performance. Yet the time-course of learning postural adjustments, the specificity of learning and the ability to effectively retain this knowledge are not well known. The objective of this research was to study the characteristics of the acquisition of postural control skills in healthy adults within a virtual environment (VE). Seven healthy young adults, aged 20-40 years (mean plusmn SD = 28.6 plusmn 2.7), performed a single training session in a VE in which maintenance of balance on a moving platform according to a given road scenario, as well as a secondary visual target reaching task were required, in repeated runs. Balance performance was assessed during training and additional assessments were performed at 24 hours and 4 weeks post-training. The results showed that the Center of Pressure (CoP) displacement decreased during the training session (P=0.001) and continued to decrease 24 hours post-training (P=0.01) (i.e., a delayed gain in skill). The gains were robustly maintained and increased by 4 (p=0.008) and 12 (p=0.005) weeks post training. New learning occurred when the secondary task was made more demanding but was not required, and when the path traveled was experienced without the secondary task or with eyes closed. Thus, a single balance maintenance training session in a VE setting was sufficient to trigger a learning process of balance control resulting in immediate gains, delayed gains and robust retention. The time-course (including the expression of delayed gains, i.e., a consolidation phase) and magnitude of this learning process appear to be similar to that which takes place during volitional manual task learning.

[1]  G. Burdea,et al.  Low-cost Virtual Rehabilitation of the Hand for Patients Post-Stroke , 2006, 2006 International Workshop on Virtual Rehabilitation.

[2]  A. Rizzo,et al.  The application of virtual reality technology in rehabilitation. , 2001 .

[3]  S. Wise,et al.  The Acquisition of Motor Behavior in Vertebrates , 1996 .

[4]  S. Adamovich,et al.  Virtual reality-augmented rehabilitation for patients following stroke. , 2002, Physical therapy.

[5]  Gerard Jounghyun Kim,et al.  A SWOT Analysis of the Field of Virtual Reality Rehabilitation and Therapy , 2005, Presence: Teleoperators & Virtual Environments.

[6]  Howard Poizner,et al.  Development and application of virtual reality technology to improve hand use and gait of individuals post-stroke. , 2004, Restorative neurology and neuroscience.

[7]  K. Doya,et al.  Parallel neural networks for learning sequential procedures , 1999, Trends in Neurosciences.

[8]  Tamar Flash,et al.  Multiple shifts in the representation of a motor sequence during the acquisition of skilled performance , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[9]  S. Scott,et al.  Random change in cortical load representation suggests distinct control of posture and movement , 2005, Nature Neuroscience.

[10]  KimGerard Jounghyun,et al.  A SWOT analysis of the field of virtual reality rehabilitation and therapy , 2005 .

[11]  J. Galen Buckwalter,et al.  Virtual Reality and Cognitive Rehabilitation: A Brief Review of the Future , 1997 .

[12]  Leslie G. Ungerleider,et al.  Functional MRI evidence for adult motor cortex plasticity during motor skill learning , 1995, Nature.

[13]  Patrice L. Weiss,et al.  Textbook of Neural Repair and Rehabilitation: Virtual reality in neurorehabilitation , 2006 .

[14]  T. Brashers-Krug,et al.  Functional Stages in the Formation of Human Long-Term Motor Memory , 1997, The Journal of Neuroscience.

[15]  A. Karni,et al.  The time course of learning a visual skill , 1993, Nature.

[16]  A. Karni,et al.  Daytime sleep condenses the time course of motor memory consolidation , 2007, Nature Neuroscience.

[17]  Leslie G. Ungerleider,et al.  The acquisition of skilled motor performance: fast and slow experience-driven changes in primary motor cortex. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[18]  A Karni,et al.  From primed to learn: the saturation of repetition priming and the induction of long-term memory. , 2002, Brain research. Cognitive brain research.

[19]  Leslie G. Ungerleider,et al.  Distinct contribution of the cortico-striatal and cortico-cerebellar systems to motor skill learning , 2003, Neuropsychologia.

[20]  Miya K. Rand,et al.  Characteristics of sequential movements during early learning period in monkeys , 2000, Experimental Brain Research.

[21]  T. Flash,et al.  When practice leads to co-articulation: the evolution of geometrically defined movement primitives , 2004, Experimental Brain Research.

[22]  M. Marusan,et al.  Virtual Reality in Neurorehabilitation : Mental Rotation , 2007 .

[23]  R. Stickgold,et al.  Practice with Sleep Makes Perfect Sleep-Dependent Motor Skill Learning , 2002, Neuron.