Honma Motoyasu, Yoshiike Takuya, Ikeda Hiroki, Kim Yoshiharu, Kuriyama Kenichi
Department of Adult Mental Health, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan.
PLoS One. 2014 Jan 17;9(1):e85734. doi: 10.1371/journal.pone.0085734. eCollection 2014.
Multisensory integration is a key factor in establishing bodily self-consciousness and in adapting humans to novel environments. The rubber hand illusion paradigm, in which humans can immediately perceive illusory ownership to an artificial hand, is a traditional technique for investigating multisensory integration and the feeling of illusory ownership. However, the long-term learning properties of the rubber hand illusion have not been previously investigated. Moreover, although sleep contributes to various aspects of cognition, including learning and memory, its influence on illusory learning of the artificial hand has not yet been assessed. We determined the effects of daily repetitive training and sleep on learning visuo-tactile-proprioceptive sensory integration and illusory ownership in healthy adult participants by using the traditional rubber hand illusion paradigm. Subjective ownership of the rubber hand, proprioceptive drift, and galvanic skin response were measured to assess learning indexes. Subjective ownership was maintained and proprioceptive drift increased with daily training. Proprioceptive drift, but not subjective ownership, was significantly attenuated after sleep. A significantly greater reduction in galvanic skin response was observed after wakefulness compared to after sleep. Our results suggest that although repetitive rubber hand illusion training facilitates multisensory integration and physiological habituation of a multisensory incongruent environment, sleep corrects illusional integration and habituation based on experiences in a multisensory incongruent environment. These findings may increase our understanding of adaptive neural processes to novel environments, specifically, bodily self-consciousness and sleep-dependent neuroplasticity.
多感官整合是建立身体自我意识以及使人类适应新环境的关键因素。橡皮手错觉范式是一种用于研究多感官整合和错觉所有权感觉的传统技术，在该范式中，人类能够立即感知到对一只假手的错觉所有权。然而，此前尚未对橡皮手错觉的长期学习特性进行研究。此外，尽管睡眠有助于认知的各个方面，包括学习和记忆，但其对假手错觉学习的影响尚未得到评估。我们通过使用传统的橡皮手错觉范式，确定了每日重复训练和睡眠对健康成年参与者学习视觉-触觉-本体感觉整合及错觉所有权的影响。测量了橡皮手的主观所有权、本体感觉漂移和皮肤电反应，以评估学习指标。随着每日训练，橡皮手的主观所有权得以维持，本体感觉漂移增加。睡眠后，本体感觉漂移显著减弱，但主观所有权未减弱。与睡眠后相比，清醒后观察到皮肤电反应的降低更为显著。我们的结果表明，尽管重复的橡皮手错觉训练促进了多感官整合以及多感官不一致环境下的生理习惯化，但睡眠会根据多感官不一致环境中的经验纠正错觉整合和习惯化。这些发现可能会增进我们对适应新环境的神经过程的理解，特别是身体自我意识和睡眠依赖性神经可塑性。
