艾宾浩斯错觉的脑形态学机制及其与冲动性人格的关系

The Brain Morphometric Mechanism of Ebbinghaus Illusion and Its Relationship to Impulsiveness

艾宾浩斯错觉是一种具有代表性的大小错觉,但是对其神经机制的探索还较为缺乏.前人的研究主要应用了功能性磁共振成像的方法,揭示了人类初级视皮层和腹侧通路在错觉形成中的作用.至今还未有研究直接探索该错觉在大脑形态学方面的神经基础.另外,作为一种稳定的错觉现象,其与人格特质的关系也值得进一步研究.因此,本研究从稳定的人格特征和脑形态学特征的个体差异出发,探究艾宾浩斯视错觉的神经机制及其与人格的关系.研究发现,艾宾浩斯错觉效应和左侧眶额叶及背外侧前额叶的灰质体积具有显著的正相关性;艾宾浩斯错觉效应和巴瑞特冲动性人格具有显著的负相关性;进一步分析发现,冲动性人格特质在左侧眶额叶灰质体积与艾宾浩斯错觉效应之间起部分中介作用,表明了冲动人格作为个体稳定的心理特征,在视错觉的形成过程中起重要作用.本研究首次尝试从人格和脑形态学两方面研究视错觉形成的认知神经基础,对理解视错觉的产生过程和现实意义具有积极的推动作用.

Ebbinghaus illusion is a typical size illusion. However, the neural mechanism of this illusion is still elusive. Previous studies mainly focused on the role of human early visual cortex and ventral pathway on Ebbinghaus illusion by using the method of f MRI. Till now, there are few studies on the brain morphometric basis of Ebbinghaus illusion. In addition, as a robust illusion, the relationship of Ebbinghaus illusion and human personality is worth studying. The current study investigated the neural mechanism of Ebbinghaus illusion and its relationship to human personality. We found that the effect of Ebbinghaus illusion was positively correlated to the regional gray matter volume of left orbitofrontal cortex（OFC） and left dorsolateral prefrontal cortex（DLPFC）; the effect of Ebbinghaus illusion was negatively correlated to the total score of Barratt Impulsiveness Scale（BIS）; impulsiveness mediated the relationship between left OFC and Ebbinghaus illusion. The results revealed that, as a stable characteristic of individuals, impulsiveness plays an important role in the generation of Ebbinghaus illusion. Our study is the first attempt to investigate the mechanism of visual illusion based on personality and brain morphometry. It advances our knowledge of visual processing and has potential practical significance.