Mazard A, Laou L, Joliot M, Mellet E
Groupe d'Imagerie Neurofonctionnelle, UMR 6194, GIP Cyceron, Bd H. Becquerel, BP 5229, 14074 CAEN Cedex, France.
Brain Res Cogn Brain Res. 2005 Aug;24(3):423-35. doi: 10.1016/j.cogbrainres.2005.02.018. Epub 2005 Apr 8.
The existence of hemispheric lateralization of visual mental imagery remains controversial. In light of the literature, we used fMRI to test whether processing of mental images of object drawings preferentially engages the left hemisphere to compared non-object drawings. An equivalent comparison was also made while participants actually perceived object and non-object drawings. Although these two conditions engaged both hemispheres, activation was significantly stronger in the left occipito-temporo-frontal network during mental inspection of object than of non-object drawings. This network was also activated when perception of object drawings was compared to that of non-object drawings. An interaction was nonetheless observed: this effect was stronger during imagery than during perception in the left inferior frontal and the left inferior temporal gyrus. Although the tasks subjects performed did not explicitly require semantic analysis, activation of this network probably reflected, at least in part, a semantic and possibly a verbal retrieval component when object drawings were processed. Mental imagery tasks elicited activation of early visual cortex at a lower level than perception tasks. In the context of the imagery debate, these findings indicate that, as previously suggested, figurative imagery could involve primary visual cortex and adjacent areas.
视觉心理意象的半球侧化现象是否存在仍存在争议。根据相关文献，我们使用功能磁共振成像（fMRI）来测试对物体图画的心理意象加工是否比非物体图画更优先地激活左半球。在参与者实际感知物体和非物体图画时，我们也进行了等效比较。尽管这两种情况都激活了两个半球，但在对物体图画进行心理检查时，左枕颞额叶网络的激活明显强于对非物体图画的激活。当比较物体图画和非物体图画的感知时，这个网络也被激活。然而，我们观察到了一种交互作用：在左额下回和左颞下回，这种效应在心理意象过程中比在感知过程中更强。尽管受试者执行的任务没有明确要求进行语义分析，但当处理物体图画时，这个网络的激活可能至少部分反映了语义以及可能的言语检索成分。心理意象任务引起的早期视觉皮层激活水平低于感知任务。在心理意象的争论背景下，这些发现表明，如先前所建议的，具象意象可能涉及初级视觉皮层和相邻区域。
