立体曲率后效的多级适应机制的fMRI证据

fMRI Evidence for Multi-level Adaptation of Stereoscopic Curvature Aftereffect

【目的】开展功能性磁共振成像适应(fMRIa)实验,验证立体曲率后效的多级适应机制在人类大脑皮层的16个ROI上的表现。【方法】通过使用水平双目视差定义的随机点立体图作为视觉刺激,设计了6种适应条件以最大限度地分离出不同的适应源。通过测量适应期间和测试期间的BOLD信号变化来评估适应强度。【结果】ANOVA分析结果表示,皮层的背侧视路和腹外侧视路均表现出对形状属性的高级适应。此外,还发现在背侧视路的V7和IPS区存在对平均视差信息的适应,说明这些区域中的低阶视差计算用于精确编码3D形状的深度结构,而腹侧视路则用于形状分类。【结论】立体曲率后效确实是由多级适应所导致。本研究成果可在虚拟现实中立体场景构建时提供对用户体验的优化。

【Purposes】 In this study,a functional resonance imaging adaptation(fMRIa) experiment was conducted to examine the multi-level adaptation mechanism in 16 ROIs of the human brain cortex.【Methods】 Random dot stereograms were defined by horizontal binocular disparity as visual stimuli.And six different adaptation conditions were designed to separate different adaptation sources.Adaptation strengthes were measured as changes in the BOLD signal between adaptation and test periods.【Findings】 ANOVA results show that both the dorsal and ventral pathways exhibit advanced adaptation effects to shape attributes.Additionally,adaptations to average disparity information in the V7 and IPS regions along the dorsal visual pathway exist,indicating that low-level disparity computations in these regions are used to precisely encode the depth structure of 3D shapes,while the ventral pathway is used for shape classification.【Conclusions】 These evidences validate the multi-evel adaptation for stereo-curvature aftereffects.The findings can provide guidance for optimizing the construction of stereoscopic scenes in virtual reality.