Hupé Jean-Michel, Dojat Michel
Centre de Recherche Cerveau et Cognition, Université de Toulouse and Centre National de la Recherche Scientifique, Toulouse France.
Grenoble Institut des Neurosciences, Institut National de la Santé et de la Recherche Médicale U836 and Université Grenoble Alpes, Grenoble France.
Front Hum Neurosci. 2015 Mar 31;9:103. doi: 10.3389/fnhum.2015.00103. eCollection 2015.
Synesthesia refers to additional sensations experienced by some people for specific stimulations, such as the systematic arbitrary association of colors to letters for the most studied type. Here, we review all the studies (based mostly on functional and structural magnetic resonance imaging) that have searched for the neural correlates of this subjective experience, as well as structural differences related to synesthesia. Most differences claimed for synesthetes are unsupported, due mainly to low statistical power, statistical errors, and methodological limitations. Our critical review therefore casts some doubts on whether any neural correlate of the synesthetic experience has been established yet. Rather than being a neurological condition (i.e., a structural or functional brain anomaly), synesthesia could be reconsidered as a special kind of childhood memory, whose signature in the brain may be out of reach with present brain imaging techniques.
联觉是指一些人在受到特定刺激时所体验到的额外感觉，比如在研究最多的类型中，颜色与字母之间存在系统性的随意关联。在此，我们回顾了所有（主要基于功能磁共振成像和结构磁共振成像）探寻这种主观体验的神经关联以及与联觉相关的结构差异的研究。大多数针对联觉者所宣称的差异缺乏依据，主要原因是统计功效低、统计误差以及方法上的局限性。因此，我们的批判性综述对是否已经确定了联觉体验的任何神经关联提出了一些质疑。与其将联觉视为一种神经病症（即大脑结构或功能异常），不如将其重新视为一种特殊的童年记忆，其在大脑中的特征可能是目前的脑成像技术无法触及的。
