理学療法ジャーナル46巻1号

2012年01月発行

特集 運動学習と理学療法

感覚刺激と運動学習

著者： 内藤栄一¹² 上原信太郎³⁴ 村田哲⁵ 出江紳一⁶

所属機関： ¹独立行政法人情報通信研究機構未来ICT研究所/脳情報通信融合研究センター ²大阪大学大学院医学研究科 ³京都大学大学院人間・環境学研究科後期博士課程 ⁴日本学術振興会 ⁵近畿大学医学部 ⁶東北大学大学院医工学研究科

ページ範囲：P.25 - P.35

はじめに

　人間が様々な運動を学習する際，実行した運動に関する感覚フィードバックは重要な役割を担う．特に，運動を実際に行う自己の身体に由来した体性感覚は本質的な役割を果たしている．体性感覚のうち，特に四肢の空間的位置や動きに関する固有受容感覚入力に障害がみられる患者では，わずか10cm程度しか手から離れていない目標に向かって手を伸ばす場合でも，正確な手の到達運動ができないことがある^1）．このような患者でも，自分の手や腕の動きに関する視覚情報があれば，正確な到達運動が可能になる．ところが，視覚の助けによって，いったんは改善したかのように見えた到達運動も，自分の手の視覚情報を遮断されてしまうと，わずか1分後には乱れ始め，数分後にはまた軌道は大きく外れる．このような現象は，健常者では観察されない．到達運動に限らず，手指第一指と残り4指との間の対立運動でも同様の現象が報告されている^2）．すなわち，視覚の助けがあると正確な対立運動が可能になるが，閉眼でこの運動を行うとわずか30秒で正確な運動ができなくなる．もちろん健常者は閉眼であっても正確にこの運動を行える．

　つまり，このような患者では，視覚の助けがあると一時的に正確な運動が可能になるが，体性感覚入力がないため，運動を獲得しにくいと考えることができる．実際，第一次体性感覚野（以下，体性感覚野）を破壊されたサルでは新規運動の習得が困難になることが示されている^3）．これらの事実は，2つの重要な点を示している．1つは運動学習における体性感覚の重要性であり，もう1つは運動制御における視覚の有用性である．そこで，本稿では主にこれらの感覚に注目し，その運動制御や学習に及ぼす影響について概説する．

参考文献

1）Ghez C, et al：Impairments of reaching movements in patients without proprioception. Ⅱ. Effects of visual information on accuracy. J Neurophysiol 73：361-372, 1995

2）Rothwell JC, et al：Manual motor performance in a deafferented man. Brain 105：515-542, 1982

3）Pavlides C, et al：Projection from the sensory to the motor cortex is important in learning motor skills in the monkey. J Neurophysiol 70：733-741, 1993

4）内藤栄一：固有知覚と身体イメージ．特集Body Image Clinical Neuroscience月刊臨床神経科学 29：905-908，2011

5）Burke D, et al：Responses to passive movement of receptors in joint, skin and muscle of the human hand. J Physiol 402：347-361, 1988

6）Goodwin GM, et al：Proprioceptive illusions induced by muscle vibration：Contribution by muscle spindles to perception? Science 175：1382-1384, 1972

7）Naito E, et al：Illusory arm movements activate cortical motor areas：A positron emission tomography study. J Neurosci 19：6134-6144, 1999

8）Naito E, et al：I feel my hand moving：A new role of the primary motor cortex in somatic perception of limb movement. Neuron 36：979-988, 2002

9）Naito E, et al：Human limb-specific and non limb-specific brain representations during kinesthetic illusory movements of the upper and lower extremities. Eur J Neurosci 25：3476-3487, 2007

10）Hagura N, et al：Activity in the posterior parietal cortex mediates visual dominance over kinesthesia. J Neurosci 27：7047-7053, 2007

11）Naito E, et al：Importance of precentral motor regions in human kinesthesia：A single case study. Neurocase 17：133-147, 2011

12）Colebatch JG, et al：Responses of monkey precentral neurones to passive movements and phasic muscle stretch：relevance to man. Electroencepharogr Clin Neurophysiol 75：44-55, 1990

13）Lehericy S, et al：3-D diffusion tensor axonal tracking shows distinct SMA and pre-SMA projections to the human striatum. Cereb Cortex 14：1302-1309, 2004

14）Lehericy S, et al：Diffusion tensor fiber tracking shows distinct corticostriatal circuits in humans. Ann Neurol 55：522-529, 2004b

15）Strick PL, et al：Cerebellum and nonmotor function. Annu Rev Neurosci 32：413-434, 2009

16）Kito T, et al：Sensory processing during kinesthetic aftereffect following illusory hand movement elicited by tendon vibration. Brain Res 1114：75-84, 2006

17）Cheney PD, et al：Corticomotoneuronal cells contribute to long-latency stretch reflexes in the rhesus monkey. J Physiol 349：249-272, 1984

18）Rosen I, et al：Peripheral afferent inputs to the forelimb area of the monkey motor cortex：Input-output relations. Exp Brain Res 14：257-273, 1972

19）Fetz EE, et al：Sensory and motor responses of precentral cortex cells during comparable passive and active joint movements. J Neurophysiol 43：1070-1089, 1980

20）Pruszynski JA, et al：Primary motor cortex underlies multi-joint integration for fast feedback control. Nature 478：387-391, 2011

21）Gallese V, et al：Action recognition in the premotor cortex. Brain 119：593-609, 1996

22）Blakemore SJ, et al：Abnormalities in the awareness of action. Trends Cognit Sci 6：237-242, 2002

23）Naito E, et al：Internally simulated movement sensations during motor imagery activate the cortical motor areas and the cerebellum. J Neurosci 22：3683-3691, 2002

24）Thyrion C, et al：Perceptual integration of illusory and imagined kinesthetic images. J Neurosci 29：8483-8492, 2009

25）Jeannerod M：The representing brain：Neural correlates of motor intention and imagery. Behav Brain Sci 17：187-245, 1994

26）Ronsse R, et al：Motor learning with augmented feedback：Modality-dependent behavioral and neural consequences. Cereb Cortex 21：1283-1294, 2011

27）Oouchida Y, et al：Your hand movements in my somatosensory cortex：A visuo-kinesthetic function in human area 2. Neuroreport 15：2019-2023, 2004

28）Hagura N, et al：Visuokinesthetic perception of hand movement is mediated by cerebro-cerebellar interaction between the left cerebellum and right parietal cortex. Cereb Cortex 19：176-186, 2009

29）Pascual-Leone A, et al：Modulation of muscle responses evoked by transcranial magnetic stimulation during the acquisition of new fine motor skills. J Neurophysiol 74：1037-1045, 1995

30）Doyon J, et al：Reorganization and plasticity in the adult brain during learning of motor skills. Curr Opin Neurobiol 15：161-167, 2005

31）Maravita A, et al：Tools for the body（schema）. Trends Cognit Sci 8：79-86, 2004

32）Murata A, et al：Representation of bodily self in the multimodal parieto-premotor network. Funahashi S（ed）：Representation and Brain, pp151-176, Springer, Heiderberg, 2007

33）Hikosaka O, et al：Parallel neural networks for learning sequential procedures. Trends Neurosci 22：464-471, 1999

34）Lehericy S, et al：Distinct basal ganglia territories are engaged in early and advanced motor sequence learning. Proc Natl Acad Sci U S A 102：12566-12571, 2005

35）Doya K：Complementary roles of basal ganglia and cerebellum in learning and motor control. Curr Opin Neurobiol 10：732-739, 2000

36）Imamizu H, et al：Brain mechanisms for predictive control by switching internal models：implications for higher-order cognitive functions. Psychol Res 73：527-544, 2009

37）Naito E, et al：Somatic sensation of hand-object interactive movement is associated with activity in the left inferior parietal cortex. J Neurosci 26：3783-3790, 2006

38）Arbib MA, et al：Tool use and the distalization of the end-effector. Psychol Res 73：441-462, 2009

39）Coynel D, et al：Dynamics of motor-related functional integration during motor sequence learning. Neuroimage 49：759-766, 2010

40）Ungerleider LG, et al：Imaging brain plasticity during motor skill learning. Neurobiol Learn Memory 78：553-564, 2002

41）Ziemann U, et al：Consensus：Motor cortex plasticity protocols. Brain Stim 1：164-182, 2008

42）Stefan K, et al：Induction of plasticity in the human motor cortex by paired associative stimulation. Brain 123：572-584, 2000

43）Ziemann U, et al：Learning modifies subsequent induction of long-term potentiation-like and long-term depression-like plasticity in human motor cortex. J Neurosci 24：1666-1672, 2004

44）Rosenkranz K, et al：Differential modulation of motor cortical plasticity and excitability in early and late phases of human motor learning. J Neurosci 27：12058-12066, 2007

45）Muellbacher W, et al：Early consolidation in human primary motor cortex. Nature 415：640-644, 2002

46）Fraser C, et al：Driving plasticity in human adult motor cortex is associated with improved motor function after brain injury. Neuron 34：831-840, 2002

47）Mckay D, et al：Time course of induction of increased human motor cortex excitability by nerve stimulation. Neuroreport 13：1271-1273, 2002

48）Ridding MC, et al：Changes in corticomotor representations induced by prolonged peripheral nerve stimulation in humans. Clin Neurophysiol 112：1461-1469, 2001

49）Chipchase LS, et al：Peripheral electrical stimulation to induce cortical plasticity：A systematic review of stimulus parameters. Clin Neurophysiol 122：456-463, 2011

50）Uehara S, et al：Improving human plateaued motor skill with somatic stimulation. PLoS One 6：e25670, 2011

51）Wu CWH, et al：Enduring representational plasticity after somatosensory stimulation. Neuroimage 27：872-884, 2005

52）Reis J, et al：Noninvasive cortical stimulation enhances motor skill acquisition over multiple days through an effect on consolidation. Proc Natl Acad Sci U S A 106：1590-1595, 2009

53）Hummel F, et al：Effects of non-invasive cortical stimulation on skilled motor function in chronic stroke. Brain 128：490-499, 2005

54）Stagg CJ, et al：Modulation of movement-associated cortical activation by transcranial direct current stimulation. Eur J Neurosci 30：1412-1423, 2009

55）Galea JM, et al：Modulation of cerebellar excitability by polarity-specific noninvasive direct current stimulation. J Neurosci 29：9115-9122, 2009

56）Galea JM, et al：Dissociating the roles of the cerebellum and motor cortex during adaptive learning：The motor cortex retains what the cerebellum learns. Cereb Cortex 21：1901-1909, 2010

57）Meunier S, et al：Changes in spinal excitability after PAS. J Neurophysiol 97：3131-3135, 2007

58）Fuentes R, et al：Spinal cord stimulation restores locomotion in animal models of Parkinson's disease. Science 323：1578-1582, 2009

59）Kilner JM, et al：An interference effect of observed biological movement on action. Curr Biol 13：522-525, 2003

60）Hirose S, et al：Viewing hand grip enhances observer's grip force in a body-part-specific manner. Neuroreport 20：1477-1480, 2009

61）Stefan K, et al：Concurrent action observation modulates practice-induced motor memory formation. Eur J Neurosci 27：730-738, 2008

62）Maslovat D, et al：Observational practice benefits are limited to perceptual improvements in the acquisition of a novel coordination skill. Exp Brain Res 204：119-130, 2010