Visually guided grasping produces fMRI activation in dorsal but not ventral stream brain areas
Visually guided grasping produces fMRI activation in dorsal but not ventral stream brain areas
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DOI：
10.1007/s00221-003-1591-5
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发表时间：
2003-11-01
影响因子：
2
通讯作者：
Goodale, MA
中科院分区：
文献类型：
--
作者：
Culham, JC;Danckert, SL;Goodale, MA
虽然伸手和抓握都需要将手移动到物体位置，但只有抓握还需要对物体的形状、大小和方向进行处理，从而使手成形。行为和神经心理学证据表明，抓取所需的物体处理依赖于介导物体识别的不同神经基质。具体来说，物体识别被认为依赖于腹侧（枕颞）流的结构，而物体抓取似乎依赖于背侧（枕顶叶）流的结构。我们使用功能性磁共振成像（fMRI）来确定抓取（与伸手相比）是否在背侧区域、腹侧区域或两者都产生激活。我们发现，在包括前顶内（AIP）皮质在内的几个区域，抓握比伸手更活跃。我们还在同一受试者中进行了标准的物体感知定位（比较完整和混乱的二维物体图像），以识别外侧枕复合体（LOC），这是一个腹侧流区域，被认为在物体识别中起着关键作用。虽然在抓握和伸手实验中呈现的物体都激活了LOC，但抓握的活动并不比伸手的活动更活跃。这些结果表明，在抓取过程中，包括AIP在内的背侧区域，而不是像LOC这样的腹侧区域，在计算物体属性方面起着基本作用。
Although both reaching and grasping require transporting the hand to the object location, only grasping also requires processing of object shape, size and orientation to preshape the hand. Behavioural and neuropsychological evidence suggests that the object processing required for grasping relies on different neural substrates from those mediating object recognition. Specifically, whereas object recognition is believed to rely on structures in the ventral (occipitotemporal) stream, object grasping appears to rely on structures in the dorsal (occipitoparietal) stream. We used functional magnetic resonance imaging (fMRI) to determine whether grasping (compared to reaching) produced activation in dorsal areas, ventral areas, or both. We found greater activity for grasping than reaching in several regions, including anterior intraparietal (AIP) cortex. We also performed a standard object perception localizer (comparing intact vs. scrambled 2D object images) in the same subjects to identify the lateral occipital complex (LOC), a ventral stream area believed to play a critical role in object recognition. Although LOC was activated by the objects presented on both grasping and reaching trials, there was no greater activity for grasping compared to reaching. These results suggest that dorsal areas, including AIP, but not ventral areas such as LOC, play a fundamental role in computing object properties during grasping.