Faillenot I, Decety J, Jeannerod M
INSERM U280, 151 cours Albert Thomas, 69003 Lyon, France.
Neuroimage. 1999 Aug;10(2):114-24. doi: 10.1006/nimg.1999.0449.
The role of the parietal cortex in visuospatial analysis of object was investigated by cerebral blood flow measurements in seven objects using positron emission tomography. Data were acquired while subjects performed a matching task requiring the discrimination of simultaneously presented objects based on one of their spatial properties. Three properties were studied separately during three scanning conditions repeated twice:surface orientation, principal axis orientation, and size. Scans were also obtained during a sensorimotor control task (similar visual stimulation, same motor action, voluntary saccades toward each object) as well as during rest (no stimulation, eyes closed). Compared to rest, the three property matching tasks showed the same pattern of activation: the whole occipital lobe, the right intraparietal sulcus (IPS), and the right occipitotemporal (OT) junction. Compared to the control condition, only right IPS and OT junction were significantly activated during discrimination of the spatial properties. The IPS focus was located between the superior parietal lobule and the angular gyrus, and the OT activation overlapped the posterior part of the inferior temporal gyrus and the middle occipital gyrus. These results indicate that discrimination of spatial attributes requires the activation of both the parietal and the temporal cortices of the right hemisphere and provide further evidence that the IPS plays a critical role in visuospatial analysis of objects.
通过正电子发射断层扫描测量七名受试者的脑血流量，研究了顶叶皮质在物体视觉空间分析中的作用。在受试者执行一项匹配任务时采集数据，该任务要求根据物体的空间属性之一来区分同时呈现的物体。在三种扫描条件下分别研究了三种属性，每种扫描条件重复两次：表面方向、主轴方向和大小。在感觉运动控制任务（类似的视觉刺激、相同的运动动作、向每个物体的自主扫视）以及休息状态（无刺激、闭眼）下也进行了扫描。与休息状态相比，三种属性匹配任务显示出相同的激活模式：整个枕叶、右侧顶内沟（IPS）和右侧枕颞（OT）交界处。与对照条件相比，在区分空间属性时，只有右侧IPS和OT交界处有明显激活。IPS的激活焦点位于顶上小叶和角回之间，OT的激活重叠了颞下回后部和枕中回。这些结果表明，空间属性的辨别需要激活右半球的顶叶和颞叶皮质，并进一步证明IPS在物体视觉空间分析中起关键作用。
