Department of Translational and Precision Medicine, "Sapienza" University of Rome, Via Benevento, 6, 00161, Roma, RM, Italy.
Brain Imaging Laboratory, Department of Psychology, "Sapienza" University of Rome, Rome, Italy.
Brain Struct Funct. 2022 Jun;227(5):1831-1842. doi: 10.1007/s00429-022-02475-0. Epub 2022 Mar 21.
Successful navigation relies on the ability to identify, perceive, and correctly process the spatial structure of a scene. It is well known that visual mental imagery plays a crucial role in navigation. Indeed, cortical regions encoding navigationally relevant information are also active during mental imagery of navigational scenes. However, it remains unknown whether their intrinsic activity and connectivity reflect the individuals' ability to imagine a scene. Here, we primarily investigated the intrinsic causal interactions among scene-selective brain regions such as Parahipoccampal Place Area (PPA), Retrosplenial Complex, and Occipital Place Area (OPA) using Dynamic Causal Modelling for resting-state functional magnetic resonance data. Second, we tested whether resting-state effective connectivity parameters among scene-selective regions could reflect individual differences in mental imagery in our sample, as assessed by the self-reported Vividness of Visual Imagery Questionnaire. We found an inhibitory influence of occipito-medial on temporal regions, and an excitatory influence of more anterior on more medial and posterior brain regions. Moreover, we found that a key role in imagery is played by the connection strength from OPA to PPA, especially in the left hemisphere, since the influence of the signal between these scene-selective regions positively correlated with good mental imagery ability. Our investigation contributes to the understanding of the complexity of the causal interaction among brain regions involved in navigation and provides new insight in understanding how an essential ability, such as mental imagery, can be explained by the intrinsic fluctuation of brain signal.
成功的导航依赖于识别、感知和正确处理场景空间结构的能力。众所周知,视觉心理意象在导航中起着至关重要的作用。事实上,编码与导航相关信息的皮质区域在导航场景的心理意象中也很活跃。然而,目前尚不清楚它们的内在活动和连接是否反映了个体想象场景的能力。在这里,我们主要使用静息态功能磁共振数据的动态因果建模来研究场景选择性脑区(如旁海马区、后扣带回复合体和枕叶区)之间的内在因果相互作用。其次,我们测试了静息态有效连接参数是否可以反映我们样本中个体在心理意象方面的差异,这是通过自我报告的视觉意象生动性问卷来评估的。我们发现,枕中内侧对颞叶区域有抑制影响,而更前侧对更内侧和更后侧脑区有兴奋影响。此外,我们发现,OPA 到 PPA 的连接强度在图像形成中起着关键作用,特别是在左半球,因为这些场景选择性区域之间的信号影响与良好的心理意象能力呈正相关。我们的研究有助于理解参与导航的脑区之间因果相互作用的复杂性,并为理解诸如心理意象等基本能力如何通过大脑信号的内在波动来解释提供了新的见解。